Fix video Call goes on hold instead of terminating when accepting 2nd video call as audio only

Make video call from A to B
Answer the call on the B as a video call
Make video call from C to A
Answer the video call as a voice call on the A.
The video call between the A and B must end

Bug: 309548300
Test: atest ImsCallingTest
Change-Id: I9887ad5e80fa0ccb775a3268e94e4c248e521311