MHF: Start DIALING_OUT_TIMEOUT for correct device

When processing Dial request, start DIALING_OUT_TIMEOUT
timer for correct matching device.
Also add null check for device retrieved from
getDeviceForMessage()

Change-Id: Id9946c6b91ca1b23a24dfe408a81db25b9dfb86a
CRs-Fixed: 612278
1 file changed