Camera2: Fix stretched preview

Camera: Fix for stretched preview in camera and camcorder...

Stretched preview is observed in front camera due to sensor's
mount angle. So resizing the preview by considering aspect ratio
of the preview.

Update preview as per aspect ratio on back key press

If user is not in full screen camera preview mode, pressing back
key will take user to full screen preview mode. During this all
views on filstrip are reloaded and shifted to full screen preview.
While reloading preview aspect ratio was not considered so user
could see stretch preview in case of front camera. This change
calls resize of preview as per aspect ratio after reload.

Aspect ratio correction for landscape mode.

In previous android versions camera application was restricted to
one mode(landscape). So aspect ratio was always calculated by just
dividing height by width. In recent versions camera application is
not restricted to landscape mode, so application needs to calcuate
aspect ratio based on mode. This change makes sure aspect ratio
calculation involves preview mode.

Change-Id: Ic90374bab801fd089d465f5de15183838f6529c8