Don't flash "No apps" while loading permissions screens on TV

This borrows from the work done in ag/722429, and:
1) makes it work for TV
2) fixes a bug in ag/722429 whereby we would show loading forever if
   preference count was 0 (as opposed to correctly showing
   "No apps" / "No permissions")

b/22090283

Change-Id: I7e2d8a4b99f99e2d1a933a2ac87494e38d2f77b9