Perform write barrier on declaring class when adding instrumentation

Since the instrumentation is marked from the declaring class we need
to mark the card so that mod-union tables and card rescanning know
about the update.

This fixes some moving GC crashes on eng builds.

Bug: 24133607

Change-Id: I66de3e3e5e1e4d2d91a041e2fbc37b93c5091b12