camera: Don't forcefully enable ZSL

Enabling ZSL without the app being aware of it is a bad idea, and can
lead to a 3rd party app trying to mix it with incompatible options with
unpredictable results. Disable it unless the camera explicitly requests
that feature.

Change-Id: Ia655f5185720cd69577c2c3006662df63e8535ef
add ISO 50 mode for d2

Change-Id: I1211150262739cced8c5c3635c5151cdaf06105c
msm8960: fix samsung camcorder mode the right way

A lot of these modes are inter-dependent. Don't mess with Samsung camera
mode if it's already been set.

There is also a problem with apps which use the FFC for video chat, that
don't set the recording hint properly. Detect them from the special
video frame rate used.

Change-Id: I8f1fc611a2f100d0438447c25103fc44917c5d87