configure default value for python

Author: msyyc

specification/storage/Storage.Management/StorageAccount.tsp

@@ -57,6 +57,14 @@ model StorageAccount
   placement?: Placement;
 }
 
+alias StorageAccountsParameters = {
+  /**
+   * May be used to expand the properties within account's properties. By default, data is not included when fetching properties. Currently we only support geoReplicationStats and blobRestoreStatus.
+   */
+  @query("$expand")
+  $expand?: StorageAccountExpand;
+};
+
 @armResourceOperations
 interface StorageAccounts {
   /**
@@ -75,13 +83,7 @@ interface StorageAccounts {
    */
   getProperties is ArmResourceRead<
     StorageAccount,
-    Parameters = {
-      /**
-       * May be used to expand the properties within account's properties. By default, data is not included when fetching properties. Currently we only support geoReplicationStats and blobRestoreStatus.
-       */
-      @query("$expand")
-      $expand?: StorageAccountExpand;
-    },
+    Parameters = StorageAccountsParameters,
     Error = ErrorResponse
   >;
 

specification/storage/Storage.Management/client.tsp

@@ -81,3 +81,9 @@ op getDeletedAccountCustomized(
   "ResourceAutoGenerated",
   "python"
 );
+
+#suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy decorator required for Python SDK compatibility"
+@@Azure.ClientGenerator.Core.Legacy.clientDefaultValue(StorageAccountsParameters.$expand,
+  "kerb",
+  "python"
+);