Fix abnormal state of ImsPhoneCall after hangup

Since there is no synchronization between the main thread
and a binder thread in which ImsCall.Lister's callback is running,
it's possible ImsPhoneCall reamins in DISCONNECTING state
when local and remote parties hangup simultaneously.

Test: aTest FrameworksTelephonyTests
Bug: 141812757
Change-Id: Ie9c666d09a12814596dc5776e45d963b96585c4d