Initialize caches os UserManagerService creation.

PIC requires initial invalidation in order to start caching. This CL invalidates all caches in UserManager at server start. This enable caching at system level and from this moment caching will be working for any context and any user.

This CL also aligns the existing cache naming to match the required standard.

Bug: 356167673
Change-Id: If34285bcbfbfcdb593c42536226d418eb25836c6
Flag: android.multiuser.caches_not_invalidated_at_start_read_only
Test: N/A