chore: Update discovery artifacts (#1317)

## Discovery Artifact Change Summary:
contentv2[ [More details]](https://github.com/googleapis/google-api-python-client/commit/85dcfe41b40f6827345fadfcccfc78f31a872e4a)
contentv21[ [More details]](https://github.com/googleapis/google-api-python-client/commit/85dcfe41b40f6827345fadfcccfc78f31a872e4a)
dnsv1beta2[ [More details]](https://github.com/googleapis/google-api-python-client/commit/5dfd888f6af29ce3bd1589683cc22255acf971c5)
realtimebiddingv1alpha[ [More details]](https://github.com/googleapis/google-api-python-client/commit/26dc108c295c1d1ab93ee13bc70f4802c4d60d2d)
serviceconsumermanagementv1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/736e39a686d43af2c49e3442066ec2cb78642792)
serviceconsumermanagementv1beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/736e39a686d43af2c49e3442066ec2cb78642792)
servicemanagementv1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/d34c2fed6e96f74b355a22c8a0fd2f0bf73898ec)
servicenetworkingv1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/67d9d5d8392b86cb004dc340884227a42b2ff06f)
servicenetworkingv1beta[ [More details]](https://github.com/googleapis/google-api-python-client/commit/67d9d5d8392b86cb004dc340884227a42b2ff06f)
serviceusagev1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/833c6db32348fc0c6e483710a0de4d5048c3fbae)
serviceusagev1beta1[ [More details]](https://github.com/googleapis/google-api-python-client/commit/833c6db32348fc0c6e483710a0de4d5048c3fbae)
diff --git a/docs/dyn/serviceusage_v1beta1.services.html b/docs/dyn/serviceusage_v1beta1.services.html
index 20b8d62..284068f 100644
--- a/docs/dyn/serviceusage_v1beta1.services.html
+++ b/docs/dyn/serviceusage_v1beta1.services.html
@@ -385,6 +385,9 @@
     },
     "endpoints": [ # Configuration for network endpoints. Contains only the names and aliases of the endpoints.
       { # `Endpoint` describes a network endpoint of a service that serves a set of APIs. It is commonly known as a service endpoint. A service may expose any number of service endpoints, and all service endpoints share the same service definition, such as quota limits and monitoring metrics. Example service configuration: name: library-example.googleapis.com endpoints: # Below entry makes 'google.example.library.v1.Library' # API be served from endpoint address library-example.googleapis.com. # It also allows HTTP OPTIONS calls to be passed to the backend, for # it to decide whether the subsequent cross-origin request is # allowed to proceed. - name: library-example.googleapis.com allow_cors: true
+        "aliases": [ # Unimplemented. Dot not use. DEPRECATED: This field is no longer supported. Instead of using aliases, please specify multiple google.api.Endpoint for each of the intended aliases. Additional names that this endpoint will be hosted on.
+          "A String",
+        ],
         "allowCors": True or False, # Allowing [CORS](https://en.wikipedia.org/wiki/Cross-origin_resource_sharing), aka cross-domain traffic, would allow the backends served from this endpoint to receive and respond to HTTP OPTIONS requests. The response will be used by the browser to determine whether the subsequent cross-origin request is allowed to proceed.
         "name": "A String", # The canonical name of this endpoint.
         "target": "A String", # The specification of an Internet routable address of API frontend that will handle requests to this [API Endpoint](https://cloud.google.com/apis/design/glossary). It should be either a valid IPv4 address or a fully-qualified domain name. For example, "8.8.8.8" or "myservice.appspot.com".
@@ -593,6 +596,9 @@
         },
         "endpoints": [ # Configuration for network endpoints. Contains only the names and aliases of the endpoints.
           { # `Endpoint` describes a network endpoint of a service that serves a set of APIs. It is commonly known as a service endpoint. A service may expose any number of service endpoints, and all service endpoints share the same service definition, such as quota limits and monitoring metrics. Example service configuration: name: library-example.googleapis.com endpoints: # Below entry makes 'google.example.library.v1.Library' # API be served from endpoint address library-example.googleapis.com. # It also allows HTTP OPTIONS calls to be passed to the backend, for # it to decide whether the subsequent cross-origin request is # allowed to proceed. - name: library-example.googleapis.com allow_cors: true
+            "aliases": [ # Unimplemented. Dot not use. DEPRECATED: This field is no longer supported. Instead of using aliases, please specify multiple google.api.Endpoint for each of the intended aliases. Additional names that this endpoint will be hosted on.
+              "A String",
+            ],
             "allowCors": True or False, # Allowing [CORS](https://en.wikipedia.org/wiki/Cross-origin_resource_sharing), aka cross-domain traffic, would allow the backends served from this endpoint to receive and respond to HTTP OPTIONS requests. The response will be used by the browser to determine whether the subsequent cross-origin request is allowed to proceed.
             "name": "A String", # The canonical name of this endpoint.
             "target": "A String", # The specification of an Internet routable address of API frontend that will handle requests to this [API Endpoint](https://cloud.google.com/apis/design/glossary). It should be either a valid IPv4 address or a fully-qualified domain name. For example, "8.8.8.8" or "myservice.appspot.com".