Fix condition where an incoming CDMA call hung up emergency call

If an incoming CDMA call happened during an emergency call,
hangup was being called, which would hang up the foreground
call (which was an emergency call).

Instead, get the TelephonyConnection associated with the call
and call onReject(), which will call the correct methods for
CDMA call waiting.

Test: manual; atest CtsTelephonyTestCases
Change-Id: I06795a484324fa94517a9e448a2dfe83a73ff051
1 file changed