Reset the invalidate cache flag when SIM phonebook is empty

The flag 'mIsCacheInvalidated' shall be cleared when there is a valid
SIM card found and it has empty SIM phonebook.

Bug: 404094844
Test: Manually tested
Flag: com.android.internal.telephony.flags.sim_phonebook_cache_fix
Change-Id: I15db3c4b2902f5b52dba0d8093ee86333b6bc616