Add properties for secrets from KV (#22652)

* add properties for secrets from KV

* typo

* remove unnecessay examples

Author: xwang971

specification/app/resource-manager/Microsoft.App/preview/2022-11-01-preview/CommonDefinitions.json

@@ -555,6 +555,14 @@
             "update"
           ],
           "x-ms-secret": true
+        },
+        "identity": {
+          "description": "Resource ID of a managed identity to authenticate with Azure Key Vault, or System to use a system-assigned identity.",
+          "type": "string"
+        },
+        "keyVaultUrl": {
+          "description": "Azure Key Vault URL pointing to the secret referenced by the container app.",
+          "type": "string"
         }
       }
     },

specification/app/resource-manager/Microsoft.App/preview/2022-11-01-preview/ContainerApps.json

@@ -881,6 +881,16 @@
           "type": "string",
           "x-ms-secret": true,
           "readOnly": true
+        },
+        "identity": {
+          "description": "Resource ID of a managed identity to authenticate with Azure Key Vault, or System to use a system-assigned identity.",
+          "type": "string",
+          "readOnly": true
+        },
+        "keyVaultUrl": {
+          "description": "Azure Key Vault URL pointing to the secret referenced by the container app.",
+          "type": "string",
+          "readOnly": true
         }
       }
     },