Formalize EXTRA_SKIP_CALL_FILTERING as system API

As part of telecom mainline prep, resolve the hidden reference from wear
services to EXTRA_SKIP_CALL_FILTERING by promoting it to a system API.

Bug: 322518197
Bug: 311773409
Test: m Telecom
Test m wear-services-calling-bluetooth & atest
WearServicesRoboTests:HfpClientConnectionServiceTest & atest
WearServicesRobotTests:HfpClientConnectionTest

Change-Id: I47b3f2d6146309157c18246e0e131bab1021c726