Reset the texture coordinates and also take aspect ratio into account.

Reset (clean) the texture coordinates before we are going to adjust the
texture coordinates. This cl also takes aspect ratio into account to
prevent the bitmap from being stretched due to the adjusted texture
coordinates.

Bug: 124355528
Bug: 126398998
Test: Manually set appropriate wallpaper, rotates the device between
portrait and landscape back and forth.

Change-Id: I76d523f6506174a9655d6ff194394f40cf78d848