Clear ImsPhoneCallTracker pending MO call on handover

If the call is handed over to CS before we receive an
onCallProgressing callback from the ImsService, clear the
pending MO call. This can happen during a silent IMS->CS
redial for emergency calls, for example.

Bug: 129727740
Test: atest FrameworksTelephonyTests
Change-Id: I88c785bd9b860f4196f28b68e71ee1ab2c40ba4d