Add missing swift/objc headers

Summary: Per title

Reviewed By: danielbuechele

Differential Revision: D15199200

fbshipit-source-id: a4251311d7fd2d22d39ba89ba0052514abbc3e2c

iOS/FlipperKit/FlipperDiagnosticsViewController.m

@@ -1,3 +1,10 @@
+/*
+ *  Copyright (c) 2018-present, Facebook, Inc.
+ *
+ *  This source code is licensed under the MIT license found in the LICENSE
+ *  file in the root directory of this source tree.
+ *
+ */
 #ifdef FB_SONARKIT_ENABLED
 
 #import "FlipperDiagnosticsViewController.h"