Allow multiple permissions in same group to auto grant

Only ignore if group has been policy fixed and nothing is
granted. Grant permission regardless of whether another
permission in the group is already granted.

Bug: 124453468
Test: Artificially set policy to auto grant and request
      multiple permissions from single group in a test app

Change-Id: I805a3ebce4b2a3df4e6d023d780df534601ea6ca