Camera: Fix camcorder crash during pause and resume

When camcorder is suspended in background, if it receives resume
and pause event in very short interval, crash will happen.
After receiving resume event, the onresume method will be called,
and it will start another thread for starting preview. And soon,
the main thread receives pause event, the onpause method which will
close camera is called.
There will be a racing between the main thread and start preview
thread. If close camera get done first, crash will be observed.
To avoid the racing, the close camera operation should wait for the
start preview operation, and the join method is used here for
synchronization.

CRs-Fixed: 526007
Change-Id: Idf6a8660378bf1a65af1f5194a35d30822f1dcf6
Camera: add config option to disable snapshots during videos

patchset2:
- disable snapshot welcome message as well
- disable jpeg quality settings

patchset3:
- minor correction

Change-Id: I5f6e14f1125a9d47e03bb35fdc4ff358c589b73e
Port camcorder touch-to-focus feature from CAF

Change-Id: I71e4122034088b00689888c4107f94d4e45ef5f6
credit: sultanxda