chore: Update discovery artifacts (#1450)

## Deleted keys were detected in the following stable discovery artifacts:
chat v1 https://github.com/googleapis/google-api-python-client/commit/8e39e1ef5482735fbaaed3be74ee472cf44cd941
dns v1 https://github.com/googleapis/google-api-python-client/commit/e2ba913fc51f78ce4b9fb6f9de97f61bd35cd356

## Deleted keys were detected in the following pre-stable discovery artifacts:
dns v1beta2 https://github.com/googleapis/google-api-python-client/commit/e2ba913fc51f78ce4b9fb6f9de97f61bd35cd356

## Discovery Artifact Change Summary:
feat(analyticsadmin): update the api https://github.com/googleapis/google-api-python-client/commit/a2e2d768e5412072ef11891ae7fb9145e2c4693d
feat(androiddeviceprovisioning): update the api https://github.com/googleapis/google-api-python-client/commit/83151f4ebd2992a53f815133304d8cb2c72d50c5
feat(chat): update the api https://github.com/googleapis/google-api-python-client/commit/8e39e1ef5482735fbaaed3be74ee472cf44cd941
feat(cloudasset): update the api https://github.com/googleapis/google-api-python-client/commit/ebd9b97ec74f0f257ccb4833f747f88d02075926
feat(cloudfunctions): update the api https://github.com/googleapis/google-api-python-client/commit/06332af99b1b1a9894bf4f553e014936225761de
feat(cloudsearch): update the api https://github.com/googleapis/google-api-python-client/commit/4aab6137bb350cb841a6b48fd37df67a209ba031
feat(content): update the api https://github.com/googleapis/google-api-python-client/commit/c65f297a775687fbfcbae827f892fc996a3d1ab1
feat(datacatalog): update the api https://github.com/googleapis/google-api-python-client/commit/af28eef0b37a5d0bb3a299f9fd9740b63f9e23bd
feat(dns): update the api https://github.com/googleapis/google-api-python-client/commit/e2ba913fc51f78ce4b9fb6f9de97f61bd35cd356
feat(documentai): update the api https://github.com/googleapis/google-api-python-client/commit/d1b9df7ee0a041d4cf632a77a626764c37e72889
feat(file): update the api https://github.com/googleapis/google-api-python-client/commit/0cd6277980d02363e3d609901d12d62b594adc92
feat(firebaseappcheck): update the api https://github.com/googleapis/google-api-python-client/commit/f8c39017aa392c0930ab79cdf7f828fe1e97e313
feat(firebasestorage): update the api https://github.com/googleapis/google-api-python-client/commit/66b6961871fea5b1a41a5b8359d7f76d6e390386
feat(gameservices): update the api https://github.com/googleapis/google-api-python-client/commit/31fd4dc22bd1e615caeafc22482caad65bbd55e9
feat(gkehub): update the api https://github.com/googleapis/google-api-python-client/commit/58ae34d8dfb4a7827b4f56e99fd48dedc64b4364
feat(ml): update the api https://github.com/googleapis/google-api-python-client/commit/15e0de32f2ea94d6ed3e0c18cd6e59cc239b37e7
feat(monitoring): update the api https://github.com/googleapis/google-api-python-client/commit/2b52d9ff5341caec20577538c0c4eaf83a896651
feat(notebooks): update the api https://github.com/googleapis/google-api-python-client/commit/c4698a84e526ab47710d2bde22827b337f2f480c
feat(people): update the api https://github.com/googleapis/google-api-python-client/commit/a646e56d40f2c7df40f48d42442c1941fc1c6674
feat(recommender): update the api https://github.com/googleapis/google-api-python-client/commit/ef997b0293c0e075208c7af15fa4e9bd6f29e883
feat(secretmanager): update the api https://github.com/googleapis/google-api-python-client/commit/489541e760eae9745724eb8cad74007903dd4f5b
feat(spanner): update the api https://github.com/googleapis/google-api-python-client/commit/acdb8fccfbb9f243f06dfff68d61cee2e58c9e45
feat(testing): update the api https://github.com/googleapis/google-api-python-client/commit/e2bde192a3e20ebd00995185cd92b47a086be8d9
diff --git a/googleapiclient/discovery_cache/documents/gkehub.v1alpha.json b/googleapiclient/discovery_cache/documents/gkehub.v1alpha.json
index ba8b186..436c97b 100644
--- a/googleapiclient/discovery_cache/documents/gkehub.v1alpha.json
+++ b/googleapiclient/discovery_cache/documents/gkehub.v1alpha.json
@@ -670,7 +670,7 @@
       }
     }
   },
-  "revision": "20210625",
+  "revision": "20210709",
   "rootUrl": "https://gkehub.googleapis.com/",
   "schemas": {
     "AuditConfig": {
@@ -1545,14 +1545,14 @@
           "additionalProperties": {
             "$ref": "MembershipFeatureSpec"
           },
-          "description": "Optional. Membership-specific configuration for this Feature. If this Feature does not support any per-Membership configuration, this field may be unused. The keys indicate which Membership the configuration is for, in the form: projects/{p}/locations/{l}/memberships/{m} Where {p} is the project, {l} is a valid location and {m} is a valid Membership in this project at that location. {p} WILL match the Feature's project. {p} will always be returned as the project number, but the project ID is also accepted during input. If the same Membership is specified in the map twice (using the project ID form, and the project number form), exactly ONE of the entries will be saved, with no guarantees as to which. For this reason, it is recommended the same format be used for all entries when mutating a Feature.",
+          "description": "Optional. Membership-specific configuration for this Feature. If this Feature does not support any per-Membership configuration, this field may be unused. The keys indicate which Membership the configuration is for, in the form: `projects/{p}/locations/{l}/memberships/{m}` Where {p} is the project, {l} is a valid location and {m} is a valid Membership in this project at that location. {p} WILL match the Feature's project. {p} will always be returned as the project number, but the project ID is also accepted during input. If the same Membership is specified in the map twice (using the project ID form, and the project number form), exactly ONE of the entries will be saved, with no guarantees as to which. For this reason, it is recommended the same format be used for all entries when mutating a Feature.",
           "type": "object"
         },
         "membershipStates": {
           "additionalProperties": {
             "$ref": "MembershipFeatureState"
           },
-          "description": "Output only. Membership-specific Feature status. If this Feature does report any per-Membership status, this field may be unused. The keys indicate which Membership the state is for, in the form: projects/{p}/locations/{l}/memberships/{m} Where {p} is the project number, {l} is a valid location and {m} is a valid Membership in this project at that location. {p} MUST match the Feature's project number.",
+          "description": "Output only. Membership-specific Feature status. If this Feature does report any per-Membership status, this field may be unused. The keys indicate which Membership the state is for, in the form: `projects/{p}/locations/{l}/memberships/{m}` Where {p} is the project number, {l} is a valid location and {m} is a valid Membership in this project at that location. {p} MUST match the Feature's project number.",
           "readOnly": true,
           "type": "object"
         },
@@ -1814,7 +1814,7 @@
       "id": "MultiClusterIngressFeatureSpec",
       "properties": {
         "billing": {
-          "description": "Customer's billing structure",
+          "description": "Deprecated: This field will be ignored and should not be set. Customer's billing structure.",
           "enum": [
             "BILLING_UNSPECIFIED",
             "PAY_AS_YOU_GO",