Connect Gxp runtime to TPU authentication service

 - Add selinux policies to allow edgetpu_app_service to access gxp
   device.

Bug: 316262348
Test: Disable selinux policies for GCA, then verify if GCA is able to
access device through edgetpu app service.

Change-Id: I83429755b1406289c8714d9499c1f14c1ec76a30
5 files changed