Add flags to cache getUserStartRealtime and getUserUnlockRealtime.

Bug: 350416205
Bug: 350421407
Change-Id: If8b2f16cb2f86e4ca4a136aef2e2a86c8d5006d4
Test: N/A
Flag: android.multiuser.cache_user_start_realtime_read_only
Flag: android.multiuser.cache_user_unlock_realtime_read_only
1 file changed