Phone: Disconnect current call if there is an active call on other sub

UE should disconnect current foregroundCall if answering
a MT call on other sub and current foregroundCall state is dialing.

CRs-Fixed: 679208

Change-Id: I6d16e92f52462050581471600d84f5fedae038bd
Add MSIM check to avoid phone app crash

Add MSIM check before calling method of MSimCallNotifier as this
class is applicable only for multisim.

Change-Id: I18d91061fd08ac8b64d3a644b11868eb9659b68b
CRs-Fixed: 685937