Update page previews and geonotahack to use new overlays

Since these are all experimental features I didn't get design input
for time being.

Also a few tweaks to mobile bridge so new overlays can be used in a desktop
environment in a usable (but ugly form)

Change-Id: Ie5fe97dc11ffd510e8bab4c8c6524f66f7979860
Merge "Update page previews and geonotahack to use new overlays"