docs: Fixing comment that caused broken Javadoc.

A comment didn't end with a period; since the comment was
being used as the summary for a Javadoc table, and included
documentation was being used as the details Javadoc comment, the
lack of a period was messing up the Javadoc formatting
( https://screenshot.googleplex.com/4cp0QHV35iW )

See first comment for doc stage location.

bug: 27130226
Change-Id: I907ffc6efa4148e98a3c35b6d03c85f50103c23a