Dedupe enable/disable IMS commands to ImsService

When sending enable/disable IMS commands, we were sending
the command twice to the ImsService due to
the same ImsServiceController being stored twice in the
mBoundImsServicesByFeature map. Instead, add the
ImsServiceControllers to a temporary set in order to
ensure that we do not accidently call the same method
twice.

Bug: 223214123
Bug: 227854958
Test: atest ImsResolverTest
Test: manual - toggled VT calling switch on TMO
Change-Id: If1eed27cb1ab8255ceb01db8e8f102a1c5dad6e2