Some fixes to the new overlay

1. Making continue and save buttons line up with the rest of the
header by giving them a -1px bottom-margin.

2. Making continue button flip in RTL languages
(Bug: 57404)

3. Fixing background position of .overlay .license so that the
graphic isn't clipped at the bottom. (18px - 16px is 2px, not 4px).

Change-Id: I97027b065e80b6057f4a0a879e2a6481c916ad84
Merge "Some fixes to the new overlay"