Camera2 : Reset mSnapshotInProgress if recording stopped.

If recording stops while snapshot is in progress, we might not get
jpeg callback because cameraservice will disable picture related
messages. Hence reset mSnapshotInProgress flag so that we can take
liveshots in the next recording session.

Change-Id: I6a639eb0b9444e4915786c65f64d3b95b064267c
CRs-Fixed: 588698