Return system theme when SecurityException is caught.

Isolated processes cannot access content resolvers so a SecurityException
will be thrown when calling getBootTheme.  This catches that
exception and returns sSystemTheme.

Change-Id: If4077adef4c657b80ba2c52a6610126dabe4ffdf
idmap: Don't log spam "CREATING STRING CACHE"

Change-Id: Idce5aa5881c8e860eca9749cc85f748303c913c0