Skip carrier priv check for trusted UIDs

Checking carrier privileges for UIDs with lots of shared apps can incur
a significant performance hit. For UIDs that are fixed and trusted
(system and phone), skip the permission check and always allow.

Also, double the cache size for getPackageInfo in order to reduce the
rate of cache misses.

Bug: 160971853
Test: manual verification -- observed lower rate of cache misses for
getPackageInfo from com.android.phone.

Change-Id: I1399cab579308479d7cf191b8795441cbcd3ff65