Feature/riteshc/swagger correctness mhsm fixes (#12209)

Author: riteshchitlangia1

specification/keyvault/resource-manager/Microsoft.KeyVault/preview/2020-04-01-preview/examples/ManagedHsm_Get.json

@@ -33,6 +33,13 @@
           "Environment": "dogfood"
         }
       }
-    }
+    },
+    "202": {
+      "headers": {
+        "Retry-After": "60",
+        "Location": "https://some.endpoint.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/hsm-group/providers/Microsoft.KeyVault/managedHSMs/hsm1?api-version=2020-04-01-preview&kv-operation=abJjb2RkIjoiAGVsZXRlTWFuYWdlZEhzbUFzeW5jYm9"
+      }
+    },
+    "204": {}
   }
 }

specification/keyvault/resource-manager/Microsoft.KeyVault/preview/2020-04-01-preview/managedHsm.json

@@ -234,6 +234,12 @@
               "$ref": "#/definitions/ManagedHsm"
             }
           },
+          "202": {
+            "description": "Accepted and the operation will complete asynchronously."
+          },
+          "204": {
+            "description": "Request successful. Resource does not exist."
+          },
           "default": {
             "description": "The error response describing why the operation failed.",
             "schema": {
@@ -394,6 +400,7 @@
         },
         "hsmUri": {
           "type": "string",
+          "readOnly": true,
           "description": "The URI of the managed hsm pool for performing operations on keys."
         },
         "enableSoftDelete": {
@@ -409,6 +416,7 @@
         },
         "enablePurgeProtection": {
           "type": "boolean",
+          "default": true,
           "description": "Property specifying whether protection against purge is enabled for this managed HSM pool. Setting this property to true activates protection against purge for this managed HSM pool and its content - only the Managed HSM service may initiate a hard, irrecoverable deletion. The setting is effective only if soft delete is also enabled. Enabling this functionality is irreversible."
         },
         "createMode": {