chore: Update discovery artifacts (#1333)

## Deleted keys were detected in the following pre-stable discovery artifacts:
gkehubv1alpha[ [More details]](https://github.com/googleapis/google-api-python-client/commit/dcd01664ac4b7e2bd428f3e42d9528c722a19a4e)
gkehubv1beta[ [More details]](https://github.com/googleapis/google-api-python-client/commit/dcd01664ac4b7e2bd428f3e42d9528c722a19a4e)

## Discovery Artifact Change Summary:
androidenterprisev1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/362d0dd463193791b3ae981b35771e2c036ae337)
androidpublisherv3[ [More details]](https://github.com/googleapis/google-api-python-client/commit/90851f695283e9e741c5df2116228f3740cee32a)
artifactregistryv1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/e77297852bb1805dfc7746332844679c42b89794)
chromepolicyv1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/cd1df57c922c4300859db216157caf3eddacbf66)
dialogflowv3beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/bd668e18902364e0de1bca6474bc4dd29b7c347f)
filev1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/804ea3bc15b7f133597a1b3c1f24e0c9c5235b54)
gkehubv1alpha[ [More details]](https://github.com/googleapis/google-api-python-client/commit/dcd01664ac4b7e2bd428f3e42d9528c722a19a4e)
gkehubv1beta[ [More details]](https://github.com/googleapis/google-api-python-client/commit/dcd01664ac4b7e2bd428f3e42d9528c722a19a4e)
lifesciencesv2beta[ [More details]](https://github.com/googleapis/google-api-python-client/commit/a1b8cf21e766625fae5f10c37f6430d20cb0f362)
servicedirectoryv1beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/b79051d8dc99227aa1ee4749e280b90d7ce7f959)

chore(acceleratedmobilepageurl): update the api
chore(adexchangebuyer): update the api
chore(adexchangebuyer2): update the api
chore(admob): update the api
chore(adsense): update the api
chore(analyticsadmin): update the api
chore(analyticsdata): update the api
chore(analyticsreporting): update the api
feat(androidenterprise): update the api
feat(androidpublisher): update the api
chore(apigateway): update the api
chore(apikeys): update the api
chore(area120tables): update the api
feat(artifactregistry): update the api
chore(bigquery): update the api
chore(blogger): update the api
chore(books): update the api
chore(chat): update the api
chore(chromemanagement): update the api
feat(chromepolicy): update the api
chore(chromeuxreport): update the api
chore(classroom): update the api
chore(cloudasset): update the api
chore(cloudbuild): update the api
chore(cloudchannel): update the api
chore(cloudprofiler): update the api
chore(cloudsearch): update the api
chore(cloudtrace): update the api
chore(containeranalysis): update the api
chore(customsearch): update the api
feat(dialogflow): update the api
chore(domainsrdap): update the api
chore(doubleclicksearch): update the api
chore(driveactivity): update the api
chore(essentialcontacts): update the api
chore(eventarc): update the api
chore(factchecktools): update the api
feat(file): update the api
chore(firebase): update the api
chore(firebasedatabase): update the api
chore(firebaseml): update the api
chore(fitness): update the api
feat(gkehub): update the api
chore(gmailpostmastertools): update the api
chore(iam): update the api
chore(iamcredentials): update the api
chore(language): update the api
chore(libraryagent): update the api
feat(lifesciences): update the api
chore(logging): update the api
chore(ml): update the api
chore(monitoring): update the api
chore(mybusinessaccountmanagement): update the api
chore(mybusinesslodging): update the api
chore(mybusinessplaceactions): update the api
chore(networkconnectivity): update the api
chore(orgpolicy): update the api
chore(osconfig): update the api
chore(pagespeedonline): update the api
chore(paymentsresellersubscription): update the api
chore(people): update the api
chore(playablelocations): update the api
chore(playcustomapp): update the api
chore(poly): update the api
chore(prod_tt_sasportal): update the api
chore(pubsublite): update the api
chore(realtimebidding): update the api
chore(recommender): update the api
chore(remotebuildexecution): update the api
chore(safebrowsing): update the api
chore(sasportal): update the api
chore(searchconsole): update the api
chore(serviceconsumermanagement): update the api
feat(servicedirectory): update the api
chore(serviceusage): update the api
chore(sheets): update the api
chore(smartdevicemanagement): update the api
chore(storage): update the api
chore(storagetransfer): update the api
chore(streetviewpublish): update the api
chore(sts): update the api
chore(tagmanager): update the api
chore(toolresults): update the api
chore(tpu): update the api
chore(vectortile): update the api
chore(videointelligence): update the api
chore(workflows): update the api
chore(youtube): update the api
chore(youtubeAnalytics): update the api
chore(youtubereporting): update the api
chore(docs): Add new discovery artifacts and reference documents
diff --git a/googleapiclient/discovery_cache/documents/artifactregistry.v1.json b/googleapiclient/discovery_cache/documents/artifactregistry.v1.json
index 39cc385..88f29ac 100644
--- a/googleapiclient/discovery_cache/documents/artifactregistry.v1.json
+++ b/googleapiclient/discovery_cache/documents/artifactregistry.v1.json
@@ -234,6 +234,71 @@
         "locations": {
           "resources": {
             "repositories": {
+              "methods": {
+                "get": {
+                  "description": "Gets a repository.",
+                  "flatPath": "v1/projects/{projectsId}/locations/{locationsId}/repositories/{repositoriesId}",
+                  "httpMethod": "GET",
+                  "id": "artifactregistry.projects.locations.repositories.get",
+                  "parameterOrder": [
+                    "name"
+                  ],
+                  "parameters": {
+                    "name": {
+                      "description": "Required. The name of the repository to retrieve.",
+                      "location": "path",
+                      "pattern": "^projects/[^/]+/locations/[^/]+/repositories/[^/]+$",
+                      "required": true,
+                      "type": "string"
+                    }
+                  },
+                  "path": "v1/{+name}",
+                  "response": {
+                    "$ref": "Repository"
+                  },
+                  "scopes": [
+                    "https://www.googleapis.com/auth/cloud-platform",
+                    "https://www.googleapis.com/auth/cloud-platform.read-only"
+                  ]
+                },
+                "list": {
+                  "description": "Lists repositories.",
+                  "flatPath": "v1/projects/{projectsId}/locations/{locationsId}/repositories",
+                  "httpMethod": "GET",
+                  "id": "artifactregistry.projects.locations.repositories.list",
+                  "parameterOrder": [
+                    "parent"
+                  ],
+                  "parameters": {
+                    "pageSize": {
+                      "description": "The maximum number of repositories to return.",
+                      "format": "int32",
+                      "location": "query",
+                      "type": "integer"
+                    },
+                    "pageToken": {
+                      "description": "The next_page_token value returned from a previous list request, if any.",
+                      "location": "query",
+                      "type": "string"
+                    },
+                    "parent": {
+                      "description": "Required. The name of the parent resource whose repositories will be listed.",
+                      "location": "path",
+                      "pattern": "^projects/[^/]+/locations/[^/]+$",
+                      "required": true,
+                      "type": "string"
+                    }
+                  },
+                  "path": "v1/{+parent}/repositories",
+                  "response": {
+                    "$ref": "ListRepositoriesResponse"
+                  },
+                  "scopes": [
+                    "https://www.googleapis.com/auth/cloud-platform",
+                    "https://www.googleapis.com/auth/cloud-platform.read-only"
+                  ]
+                }
+              },
               "resources": {
                 "dockerImages": {
                   "methods": {
@@ -283,7 +348,7 @@
       }
     }
   },
-  "revision": "20210415",
+  "revision": "20210423",
   "rootUrl": "https://artifactregistry.googleapis.com/",
   "schemas": {
     "CancelOperationRequest": {
@@ -370,6 +435,24 @@
       },
       "type": "object"
     },
+    "ListRepositoriesResponse": {
+      "description": "The response from listing repositories.",
+      "id": "ListRepositoriesResponse",
+      "properties": {
+        "nextPageToken": {
+          "description": "The token to retrieve the next page of repositories, or empty if there are no more repositories to return.",
+          "type": "string"
+        },
+        "repositories": {
+          "description": "The repositories returned.",
+          "items": {
+            "$ref": "Repository"
+          },
+          "type": "array"
+        }
+      },
+      "type": "object"
+    },
     "Operation": {
       "description": "This resource represents a long-running operation that is the result of a network API call.",
       "id": "Operation",
@@ -405,6 +488,54 @@
       },
       "type": "object"
     },
+    "Repository": {
+      "description": "A Repository for storing artifacts with a specific format.",
+      "id": "Repository",
+      "properties": {
+        "createTime": {
+          "description": "The time when the repository was created.",
+          "format": "google-datetime",
+          "type": "string"
+        },
+        "description": {
+          "description": "The user-provided description of the repository.",
+          "type": "string"
+        },
+        "format": {
+          "description": "The format of packages that are stored in the repository.",
+          "enum": [
+            "FORMAT_UNSPECIFIED",
+            "DOCKER"
+          ],
+          "enumDescriptions": [
+            "Unspecified package format.",
+            "Docker package format."
+          ],
+          "type": "string"
+        },
+        "kmsKeyName": {
+          "description": "The Cloud KMS resource name of the customer managed encryption key that\u2019s used to encrypt the contents of the Repository. Has the form: `projects/my-project/locations/my-region/keyRings/my-kr/cryptoKeys/my-key`. This value may not be changed after the Repository has been created.",
+          "type": "string"
+        },
+        "labels": {
+          "additionalProperties": {
+            "type": "string"
+          },
+          "description": "Labels with user-defined metadata. This field may contain up to 64 entries. Label keys and values may be no longer than 63 characters. Label keys must begin with a lowercase letter and may only contain lowercase letters, numeric characters, underscores, and dashes.",
+          "type": "object"
+        },
+        "name": {
+          "description": "The name of the repository, for example: \"projects/p1/locations/us-central1/repositories/repo1\".",
+          "type": "string"
+        },
+        "updateTime": {
+          "description": "The time when the repository was last updated.",
+          "format": "google-datetime",
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
     "Status": {
       "description": "The `Status` type defines a logical error model that is suitable for different programming environments, including REST APIs and RPC APIs. It is used by [gRPC](https://github.com/grpc). Each `Status` message contains three pieces of data: error code, error message, and error details. You can find out more about this error model and how to work with it in the [API Design Guide](https://cloud.google.com/apis/design/errors).",
       "id": "Status",