camera: Make the popup menu transparent

 * We should never obscure the preview.

Change-Id: I246f82808f1277f719b9bedafb6d3ace833cc48e

camera: Tweak the popup transparency

 * Currently too hard to read with bright images.

Change-Id: Ica2a77491296637c0b56f886bad704b8b4fcd5c8

Conflicts:
	res/values/colors.xml
Change-Id: I120bd0080929d87c653372b68e3a0f5334f5f689