chore: Update discovery artifacts (#1344)

chore: update docs/dyn/index.md
chore(acceleratedmobilepageurl): update the api
chore(accesscontextmanager): update the api
chore(adexchangebuyer): update the api
chore(adexchangebuyer2): update the api
chore(admob): update the api
chore(adsense): update the api
feat(analyticsadmin): update the api
chore(analyticsdata): update the api
chore(androiddeviceprovisioning): update the api
chore(androidpublisher): update the api
chore(apigateway): update the api
chore(apigee): update the api
chore(apikeys): update the api
chore(appengine): update the api
chore(area120tables): update the api
chore(artifactregistry): update the api
feat(bigquery): update the api
chore(bigqueryconnection): update the api
chore(bigqueryreservation): update the api
chore(bigtableadmin): update the api
chore(binaryauthorization): update the api
chore(blogger): update the api
chore(books): update the api
chore(calendar): update the api
chore(chat): update the api
chore(chromemanagement): update the api
chore(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(clouddebugger): update the api
chore(clouderrorreporting): update the api
chore(cloudfunctions): update the api
chore(cloudidentity): update the api
chore(cloudiot): update the api
chore(cloudkms): update the api
chore(cloudprofiler): update the api
chore(cloudresourcemanager): update the api
chore(cloudsearch): update the api
chore(cloudshell): update the api
chore(cloudtrace): update the api
chore(container): update the api
chore(containeranalysis): update the api
chore(content): update the api
chore(customsearch): update the api
chore(dataflow): update the api
chore(deploymentmanager): update the api
chore(dialogflow): update the api
chore(displayvideo): update the api
chore(dlp): update the api
feat(documentai): update the api
chore(domainsrdap): update the api
chore(doubleclickbidmanager): 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
chore(fcm): update the api
chore(file): update the api
chore(firebase): update the api
chore(firebasedatabase): update the api
chore(firebaseml): update the api
chore(fitness): update the api
chore(games): update the api
chore(gamesConfiguration): update the api
chore(gamesManagement): update the api
feat(gameservices): update the api
chore(genomics): update the api
chore(gkehub): update the api
chore(gmail): update the api
chore(gmailpostmastertools): update the api
chore(groupssettings): update the api
chore(healthcare): update the api
chore(homegraph): update the api
chore(iam): update the api
chore(iamcredentials): update the api
chore(iap): update the api
chore(language): update the api
chore(libraryagent): update the api
chore(lifesciences): update the api
chore(memcache): update the api
chore(metastore): update the api
chore(ml): update the api
feat(monitoring): update the api
feat(mybusinessaccountmanagement): update the api
chore(mybusinesslodging): update the api
chore(mybusinessplaceactions): update the api
feat(networkmanagement): update the api
chore(ondemandscanning): update the api
chore(orgpolicy): update the api
chore(osconfig): update the api
feat(oslogin): 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(policysimulator): update the api
chore(poly): update the api
chore(privateca): update the api
chore(prod_tt_sasportal): update the api
chore(pubsub): update the api
feat(pubsublite): update the api
chore(realtimebidding): update the api
feat(recommender): update the api
chore(redis): update the api
chore(remotebuildexecution): update the api
chore(reseller): update the api
chore(retail): update the api
chore(run): update the api
chore(safebrowsing): update the api
chore(sasportal): update the api
chore(searchconsole): update the api
chore(secretmanager): update the api
chore(securitycenter): update the api
chore(serviceconsumermanagement): update the api
feat(servicenetworking): update the api
chore(serviceusage): update the api
chore(slides): update the api
chore(sourcerepo): update the api
chore(speech): update the api
chore(sqladmin): 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(tasks): update the api
chore(testing): update the api
chore(toolresults): update the api
chore(tpu): update the api
chore(trafficdirector): update the api
chore(vault): update the api
chore(vectortile): update the api
chore(vision): update the api
chore(webrisk): update the api
chore(workflowexecutions): 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/paymentsresellersubscription.v1.json b/googleapiclient/discovery_cache/documents/paymentsresellersubscription.v1.json
index ed988e3..c700e6b 100644
--- a/googleapiclient/discovery_cache/documents/paymentsresellersubscription.v1.json
+++ b/googleapiclient/discovery_cache/documents/paymentsresellersubscription.v1.json
@@ -221,7 +221,7 @@
                   "type": "string"
                 },
                 "subscriptionId": {
-                  "description": "Required. Identifies the subscription resource on the Partner side. If a subscription was previously created with the same subscription_id, we will directly return that one.",
+                  "description": "Required. Identifies the subscription resource on the Partner side. The value is restricted to 63 ASCII characters at the maximum. If a subscription was previously created with the same subscription_id, we will directly return that one.",
                   "location": "query",
                   "type": "string"
                 }
@@ -323,7 +323,7 @@
                   "type": "string"
                 },
                 "subscriptionId": {
-                  "description": "Required. Identifies the subscription resource on the Partner side. If a subscription was previously created with the same subscription_id, we will directly return that one.",
+                  "description": "Required. Identifies the subscription resource on the Partner side. The value is restricted to 63 ASCII characters at the maximum. If a subscription was previously created with the same subscription_id, we will directly return that one.",
                   "location": "query",
                   "type": "string"
                 }
@@ -366,7 +366,7 @@
       }
     }
   },
-  "revision": "20210502",
+  "revision": "20210507",
   "rootUrl": "https://paymentsresellersubscription.googleapis.com/",
   "schemas": {
     "GoogleCloudPaymentsResellerSubscriptionV1CancelSubscriptionRequest": {
@@ -385,6 +385,7 @@
             "CANCELLATION_REASON_ACCIDENTAL_PURCHASE",
             "CANCELLATION_REASON_PAST_DUE",
             "CANCELLATION_REASON_ACCOUNT_CLOSED",
+            "CANCELLATION_REASON_UPGRADE_DOWNGRADE",
             "CANCELLATION_REASON_OTHER"
           ],
           "enumDescriptions": [
@@ -394,6 +395,7 @@
             "Accidential purchase.",
             "Payment is past due.",
             "User account closed.",
+            "Used for notification only, do not use in Cancel API. Cancallation due to upgrade or downgrade.",
             "Other reason."
           ],
           "type": "string"
@@ -670,7 +672,7 @@
           "type": "string"
         },
         "partnerUserToken": {
-          "description": "Required. Identifier of the end-user in partner\u2019s system.",
+          "description": "Required. Identifier of the end-user in partner\u2019s system. The value is restricted to 63 ASCII characters at the maximum.",
           "type": "string"
         },
         "products": {
@@ -739,6 +741,7 @@
             "CANCELLATION_REASON_ACCIDENTAL_PURCHASE",
             "CANCELLATION_REASON_PAST_DUE",
             "CANCELLATION_REASON_ACCOUNT_CLOSED",
+            "CANCELLATION_REASON_UPGRADE_DOWNGRADE",
             "CANCELLATION_REASON_OTHER"
           ],
           "enumDescriptions": [
@@ -748,6 +751,7 @@
             "Accidential purchase.",
             "Payment is past due.",
             "User account closed.",
+            "Used for notification only, do not use in Cancel API. Cancallation due to upgrade or downgrade.",
             "Other reason."
           ],
           "type": "string"