Language list heading: add padding and make it bold [DO NOT MERGE]

This makes it consistent with heading labels used in other areas
of the Settings app.

Bug: 26758145
Change-Id: I9b66e97b5a0a8b0646e4b345b25b6d93178fc8e6
(cherry picked from commit 5d1e9977350b85828f3ba533f3bf9d17917a9977)
1 file changed