Bug 1056096 - Always prefer higher preview resolution than screen

In cases when there is no supported preview resolution that exactly
matches the (taken) picture aspect ratio AND the viewport height,
we would use the preview resolution that matches the viewport height the
closest. When this match was smaller than the viewport size, the preview
stream from camera would appear blurry.

This patch prioritizes a larger resolution than the viewport size and
defaults to the closest match if there are no larger resolutions
available.