More tweaks to match UX spec.

Fixed text colors to match spec.  Behold The Greyening!  Centered
loader spinner in grid mode.  Show multiple lines in status messages.

Add string descriptions.  Fix bug where toggling size setting didn't
kick a UI rebind.

Bug: 10510022
Change-Id: Icb41ebeb4de0fed8c04fc6cf5213af1587b72641