Camera: Fix deadlock due to mLock in pcb and takepicture

In non-zsl case of takepicture, we do streamoff for preview
stream which is waiting on preview callback thread to exit.
By that time the lock has already been acquired by takePicture.
So preivew callback will not exit until it acquires lock and
takePicture cannot continue until PCB call back is returned.
Fix: Avoid the mLock at services when both Preview cb &
Compressed cb are enabled.

Change-Id: I61ffa60af34a3fc19b8f45c119535243b53c7d3c