Revert "isolated_app: Do not allow access to the gpu_device."

Chrome team recommends reverting this patch and introducing
it into a future version of Android, to avoid potential
compatibility issues.

This reverts commit 9de62d6f.

Bug: 17471434
Bug: 18609318
Change-Id: I3086cb8a8d7142b1eadce622f7e87a4c3426b6bf