st-hal: fix pause and detection events concurrency issue

pause event in state machine is dispatched without proxy session
lock held, which causes synchronization issue when state machine
is already handling a detection event there by keeping sthal in
unexpected state leading to no further detection.

Fix it by using proxy session lock when dispatching pause event.

Change-Id: I8d93d06fdc7d8d4024a3586ebaa6c9f41d293786
1 file changed