fix(serviceusage): update the API

#### serviceusage:v1beta1

The following keys were changed:
- schemas.DocumentationRule.properties.description.description
- schemas.MonitoredResourceDescriptor.properties.type.description

#### serviceusage:v1

The following keys were changed:
- schemas.DocumentationRule.properties.description.description
- schemas.MonitoredResourceDescriptor.properties.type.description

discovery/serviceusage-v1.json

@@ -426,7 +426,7 @@
       }
     }
   },
-  "revision": "20210707",
+  "revision": "20210804",
   "rootUrl": "https://serviceusage.googleapis.com/",
   "schemas": {
     "AdminQuotaPolicy": {
@@ -1000,7 +1000,7 @@
           "type": "string"
         },
         "description": {
-          "description": "The description is the comment in front of the selected proto element, such as a message, a method, a 'service' definition, or a field.",
+          "description": "Description of the selected proto element (e.g. a message, a method, a 'service' definition, or a field). Defaults to leading & trailing comments taken from the proto source definition of the proto element.",
           "type": "string"
         },
         "selector": {
@@ -2100,7 +2100,7 @@
           "type": "string"
         },
         "type": {
-          "description": "Required. The monitored resource type. For example, the type `\"cloudsql_database\"` represents databases in Google Cloud SQL.",
+          "description": "Required. The monitored resource type. For example, the type `\"cloudsql_database\"` represents databases in Google Cloud SQL. For a list of types, see [Monitoring resource types](https://cloud.google.com/monitoring/api/resources) and [Logging resource types](https://cloud.google.com/logging/docs/api/v2/resource-list).",
           "type": "string"
         }
       },

discovery/serviceusage-v1beta1.json

@@ -959,7 +959,7 @@
       }
     }
   },
-  "revision": "20210707",
+  "revision": "20210804",
   "rootUrl": "https://serviceusage.googleapis.com/",
   "schemas": {
     "AdminQuotaPolicy": {
@@ -1565,7 +1565,7 @@
           "type": "string"
         },
         "description": {
-          "description": "The description is the comment in front of the selected proto element, such as a message, a method, a 'service' definition, or a field.",
+          "description": "Description of the selected proto element (e.g. a message, a method, a 'service' definition, or a field). Defaults to leading & trailing comments taken from the proto source definition of the proto element.",
           "type": "string"
         },
         "selector": {
@@ -2783,7 +2783,7 @@
           "type": "string"
         },
         "type": {
-          "description": "Required. The monitored resource type. For example, the type `\"cloudsql_database\"` represents databases in Google Cloud SQL.",
+          "description": "Required. The monitored resource type. For example, the type `\"cloudsql_database\"` represents databases in Google Cloud SQL. For a list of types, see [Monitoring resource types](https://cloud.google.com/monitoring/api/resources) and [Logging resource types](https://cloud.google.com/logging/docs/api/v2/resource-list).",
           "type": "string"
         }
       },

src/apis/serviceusage/v1.ts

@@ -533,7 +533,7 @@ export namespace serviceusage_v1 {
      */
     deprecationDescription?: string | null;
     /**
-     * The description is the comment in front of the selected proto element, such as a message, a method, a 'service' definition, or a field.
+     * Description of the selected proto element (e.g. a message, a method, a 'service' definition, or a field). Defaults to leading & trailing comments taken from the proto source definition of the proto element.
      */
     description?: string | null;
     /**
@@ -1260,7 +1260,7 @@ export namespace serviceusage_v1 {
      */
     name?: string | null;
     /**
-     * Required. The monitored resource type. For example, the type `"cloudsql_database"` represents databases in Google Cloud SQL.
+     * Required. The monitored resource type. For example, the type `"cloudsql_database"` represents databases in Google Cloud SQL. For a list of types, see [Monitoring resource types](https://cloud.google.com/monitoring/api/resources) and [Logging resource types](https://cloud.google.com/logging/docs/api/v2/resource-list).
      */
     type?: string | null;
   }

src/apis/serviceusage/v1beta1.ts

@@ -569,7 +569,7 @@ export namespace serviceusage_v1beta1 {
      */
     deprecationDescription?: string | null;
     /**
-     * The description is the comment in front of the selected proto element, such as a message, a method, a 'service' definition, or a field.
+     * Description of the selected proto element (e.g. a message, a method, a 'service' definition, or a field). Defaults to leading & trailing comments taken from the proto source definition of the proto element.
      */
     description?: string | null;
     /**
@@ -1369,7 +1369,7 @@ export namespace serviceusage_v1beta1 {
      */
     name?: string | null;
     /**
-     * Required. The monitored resource type. For example, the type `"cloudsql_database"` represents databases in Google Cloud SQL.
+     * Required. The monitored resource type. For example, the type `"cloudsql_database"` represents databases in Google Cloud SQL. For a list of types, see [Monitoring resource types](https://cloud.google.com/monitoring/api/resources) and [Logging resource types](https://cloud.google.com/logging/docs/api/v2/resource-list).
      */
     type?: string | null;
   }