Add a new method to unregister ImsFeatureStatusCallbacks

Bug: 156893040
Fixes: 157948894
Test: atest FrameworksTelephonyTests
Merged-In: I9826f25984510124317a5f271e83f9c0c81af3d3
Change-Id: I9826f25984510124317a5f271e83f9c0c81af3d3
1 file changed