Overlay custom TextAppearances rather than nuke

Currently if a developer sets a custom TextAppearance
on CollapsingToolbarLayout without a text size, it breaks
since it doesn't have a text size to use.

This is fixed by always loading the default text appearances
first, and then overlaying any custom styles.

Also fixed the new margin top.

BUG: 22316083
Change-Id: I762698120cda501f6e335e41f8ceb82a246627c9
3 files changed