add update_transform protos

Author: Brian Chen

packages/firestore/src/protos/firestore_proto_api.d.ts

@@ -391,6 +391,7 @@ export declare namespace firestoreV1ApiClientInterfaces {
     verify?: string;
     transform?: DocumentTransform;
     updateMask?: DocumentMask;
+    updateTransform?: FieldTransform[];
     currentDocument?: Precondition;
   }
   interface WriteRequest {

packages/firestore/src/protos/google/firestore/v1/write.proto

@@ -66,6 +66,13 @@ message Write {
   // The field paths in this mask must not contain a reserved field name.
   DocumentMask update_mask = 3;
 
+  // The transforms to perform after update.
+  //
+  // This field can be set only when the operation is `update`. If present, this
+  // write is equivalent to performing `update` and `transform` to the same
+  // document atomically and in order.
+  repeated DocumentTransform.FieldTransform update_transforms = 7;
+
   // An optional precondition on the document.
   //
   // The write will fail if this is set and not met by the target document.