Fix checkstyle import ordering issues

Fix checkstyle import ordering issues. These have been introduced
by various commits, all in goog/master.

This fixes the ordering before I land unrelated changes.

Commits:
640f30a7
782043ca
35cda394
a38fbf63

Bug: 37984816
Test: make -j30 droid
Change-Id: I158dcf38c024a294d38cdb40f8909d5d5113b199