Enable checkstyle everywhere in frameworks/base.

This was done in internal master in ag/5397886. Do it in AOSP as
well so we can benefit from checkstyle in AOSP as well.

Test: None
Change-Id: Ib00fc8d318e8127224846e0a69cb542178631437
Merged-In: I7d350c2bbb9fcd1019abd1addb035ce5e9e05acc
1 file changed