Decouple the ImsFeature status listener from creating the feature

Add the listener after the ImsFeature has been created to ensure
that listeners do not miss the state update due to the feature not
being tracked internally yet.

(This is part 1 of a two part process to clean up ImsFeature
connecting).

Test: atest CtsTelephonyTestCases FrameworksTelephonyTests ImsCommonTests
Change-Id: I6a0cf4a4dfae2593ea77d3b098cd7a93325ea740