Unexpose unnecessary SysUI APIs

These APIs were exposed for mainline since they were used in SysUI code,
but the logic that was using them was moved to Telephony. Unexposing the
APIs since they no longer need to be exposed.

Test: atest FrameworksTelephonyTests
Bug: 147447171
Bug: 111498835
Bug: 149874525
Change-Id: I1930977c5345c075773d18db4eb05913038d7e7f