Don't call onStartRtt unless RTT property changes

Don't call onStartRtt inside the call connection property change unless
the RTT property flipped to on -- this'll send spurious RTT requests if
RTT was already on.

Change-Id: If8ee4e9bf994f1ed6c6fc58c3f224445493f9c5d
Merged-In: If8ee4e9bf994f1ed6c6fc58c3f224445493f9c5d
Fixes: 110855750
Test: manual
1 file changed