When there is no VM support hide the tab in the Old Main Activity

In the case where the user is not able to dial into the voicemail tab, or there exists another voicemail app, or VVM is not supported, we do not want to show the VM tab.

This CL does not update the activity when a sim is inserted/removed.

Bug: 73123614
Test: Unit tests
PiperOrigin-RevId: 186433072
Change-Id: I0396b1e15c9a4740eee721af89dbfdf95696cace
2 files changed