chore: Update discovery artifacts (#1306)

## Deleted keys were detected in the following pre-stable discovery artifacts:
bigqueryreservationv1beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/6a8b3c6bd7aef8c84d5ba64410b29cabf056102b)

## Discovery Artifact Change Summary:
adexchangebuyer2v2beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/949754477e811a0b490a35e7e7313bbd22918d8a)
artifactregistryv1beta2[ [More details]](https://github.com/googleapis/google-api-python-client/commit/3811667db343c8e4ca5479b668a14b4bceddd981)
bigquerydatatransferv1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/f0071f5468eaa0320920fbee1489dbc2cb5e195f)
bigqueryreservationv1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/6a8b3c6bd7aef8c84d5ba64410b29cabf056102b)
bigqueryreservationv1beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/6a8b3c6bd7aef8c84d5ba64410b29cabf056102b)
bigtableadminv2[ [More details]](https://github.com/googleapis/google-api-python-client/commit/d1ce2408cf8bf7deaab38f7ecff96e9cb5d5a02d)
containerv1beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/60a23f0cafcca5473a829e8b11280733f76a8271)
displayvideov1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/559fa7cf4c7d300947bb556eb8c2830a751c7b11)
loggingv2[ [More details]](https://github.com/googleapis/google-api-python-client/commit/a3c1055968a4d9ac2448b0540bf4e2005be2958f)
serviceusagev1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/e2a86e92aa0ab7cce0b936a764ea5440b35a62e9)
serviceusagev1beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/e2a86e92aa0ab7cce0b936a764ea5440b35a62e9)
diff --git a/googleapiclient/discovery_cache/documents/serviceusage.v1.json b/googleapiclient/discovery_cache/documents/serviceusage.v1.json
index 0a234fd..32edecb 100644
--- a/googleapiclient/discovery_cache/documents/serviceusage.v1.json
+++ b/googleapiclient/discovery_cache/documents/serviceusage.v1.json
@@ -4,6 +4,12 @@
       "scopes": {
         "https://www.googleapis.com/auth/cloud-platform": {
           "description": "See, edit, configure, and delete your Google Cloud Platform data"
+        },
+        "https://www.googleapis.com/auth/cloud-platform.read-only": {
+          "description": "View your data across Google Cloud Platform services"
+        },
+        "https://www.googleapis.com/auth/service.management": {
+          "description": "Manage your Google API service configuration"
         }
       }
     }
@@ -132,7 +138,8 @@
             "$ref": "Empty"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/service.management"
           ]
         },
         "delete": {
@@ -157,7 +164,8 @@
             "$ref": "Empty"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/service.management"
           ]
         },
         "get": {
@@ -182,7 +190,8 @@
             "$ref": "Operation"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/service.management"
           ]
         },
         "list": {
@@ -219,7 +228,8 @@
             "$ref": "ListOperationsResponse"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/service.management"
           ]
         }
       }
@@ -251,7 +261,8 @@
             "$ref": "Operation"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/service.management"
           ]
         },
         "batchGet": {
@@ -282,7 +293,8 @@
             "$ref": "BatchGetServicesResponse"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/cloud-platform.read-only"
           ]
         },
         "disable": {
@@ -310,7 +322,8 @@
             "$ref": "Operation"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/service.management"
           ]
         },
         "enable": {
@@ -338,7 +351,8 @@
             "$ref": "Operation"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/service.management"
           ]
         },
         "get": {
@@ -363,7 +377,8 @@
             "$ref": "GoogleApiServiceusageV1Service"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/cloud-platform.read-only"
           ]
         },
         "list": {
@@ -404,13 +419,14 @@
             "$ref": "ListServicesResponse"
           },
           "scopes": [
-            "https://www.googleapis.com/auth/cloud-platform"
+            "https://www.googleapis.com/auth/cloud-platform",
+            "https://www.googleapis.com/auth/cloud-platform.read-only"
           ]
         }
       }
     }
   },
-  "revision": "20210417",
+  "revision": "20210422",
   "rootUrl": "https://serviceusage.googleapis.com/",
   "schemas": {
     "AdminQuotaPolicy": {