IMS: Fix issue of answering calls for some 3rd party apps

Allow base ConnectionService class to invoke onAnswer()
method of connection when answer request without videostate
is called.

Change-Id: I8ac1ae7a584bc913f2259a1bc8483e63a33e2250
CRs-Fixed: 2921144
Issue: FP3-A13#56
(cherry picked from commit 77897882489a6f762faea2673d25f0a050a2119e)
1 file changed