Set original camera parameters while switching between modules.

Camera holder maintains a local variable to get original params
and set those params back when user switch between modules. But
these parameters were obtained from the instance of camera manager.
So object in Camera holder will be a reference to an object in
camera manager. Becasue of this all the parameters set in photo
module are getting reflected in other modules.
This change makes sure the camera holder's parameters object is
created separately by getting data from camera device.
Also reverted the alternative solution to reset scene mode in
video and panorama module.

CRs-Fixed: 579747

Change-Id: I02637fb2c215aeb1ba9076629400a339c31178ad
Camera: Enable module switcher on resume

For HDR mode, on pressing shutter key, module switcher icon will be
turned off. That'll not be activated if user relaunch camera
after pressing home key in HDR mode while capturing image.

Enable switcher in UI on resuming camera module.

Change-Id: I094f4941f87149e4c5b2393881ed5175c4388559
CRs-fixed: 580450