Camera: Fix for stretched preview in front camera

Stretched preview is observed due to front camera's mount angle.
This patch resizes preview frame using aspect ratios so preview is not
stretched when using the front camera in still and camcorder mode.

Change-Id: I70b5534dd3020bdf46afdfdcefc39d89a2b2e450
CRs-fixed: 435942

Camera: Fixes stretched preview in camera application

- The preview screen nail is getting set with the
  preview frame layout size, which depending on the
  preview resolution might lead to aspect ratio
  mismatches.

Change-Id: Ifdc436feffefa4ad95d3915f48724b0fc3684d9d

Camera: Updates preview screen nail correctly

- Querying the width and height of the screen nail
  currently will return the render width and height
  which in turn depend on the preview frame layout
  size. In cases where both sizes match the screen
  nail will not get updated properly. Instead of
  using the render width and height this change
  uses the actual size of the nail itself.
  This way changes to the resolutions are
  recognized properly and the nail is updated.
- This patch also removes 'updateCameraScreenNailSize()'
  and extends the functionality of 'startPreview()'
  in order to update the screen nail for the cases
  where the preview and the nail size don't match.

Change-Id: Ib99f47f4094e01724725098847f42197b4442c03