Revert [Telephony mainline] Add SystemApi and NonNull annotation

Reason: Revisit and redesign in S

Bug: 147390517
Test: make
Change-Id: I0749492a5648dfa2fb83271f349a8370972f7032
Merged-In: I0749492a5648dfa2fb83271f349a8370972f7032
(cherry picked from commit 2d280f1bb4f3007eea5ca71e431104fb47f9a92d)
2 files changed