CTS: Fixes a possible "out of memory" exception

- Image sizes can vary quite a bit. Some cameras might
  support up to 12MP picture sizes, which can result
  in very large bitmaps. Dalvik's VM stack size might
  not be able to handle arrays of this size.
  In these cases an "out of memory" exception
  is possible.
- Related to test cases #testPreviewPictureSizesCombination,
  #testTakePicture and #testJpegThumbnailSizeByCamera.

Change-Id: I15406f73bb72c897b04876f312019dc68f0f726f
Signed-off-by: Emilian Peev <epeev@mm-sol.com>