Add trailing comma required by style guide
Add trailing comma required by style guide

RELNOTES: n/a

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=278694940

lucidsoftware/closure-library,lucidsoftware/closure-library,google/closure-library,lucidsoftware/closure-library,google/closure-library,google/closure-library,google/closure-library,google/closure-library,lucidsoftware/closure-library