Telephony registry is running in the system process. When receiving
the binder call from phone, after checking the permission, it should
perform actions in system's identity.

Bug: 271892778
Test: Boot up
Test: Basic phone functionality tests
Test: atest TelephonyRegistryTest
Change-Id: I761b9a73f7654eea14d08f7d2602978d32aedffc
Merged-In: I761b9a73f7654eea14d08f7d2602978d32aedffc