Consolidate naming of dimens in car-support-lib.

Normalize the naming of various car styles so that they are the same
across dimens, colors and styles. For example, Headline 1 used to
represented as "headline1" and "headline_1." Now, only the former will
exist.

Test: Visually inspected
Bug: 31399929
Change-Id: I240563dfaaed710372fd805d812dd446fa1f6478
(cherry picked from commit 90bc57f834291a83b036dccbf9c17127665a0feb)
3 files changed