Notify ImsService Status Correctly

Modifies ImsService to allow multiple status callbacks in
for one ImsFeature. This better handles one ImsFeature
for normal/emergency calling.

Bug: 38001858
Test: Unit Testing
Merged-In: I70ae6f5349aef75aa86d54fe37a3c32459ea3afa
Change-Id: I70ae6f5349aef75aa86d54fe37a3c32459ea3afa