Merge branch 'stable-3.1'

* stable-3.1:
  Format Java files with google-java-format
  Add missing newline at end of tools/BUILD
  Format Java files with google-java-format
  Update external dependencies
  Revert "Remove Tika dependency for uploadvalidator"
  Add test for mime type detection

Change-Id: I8dba5f634b4326d0c429d30632f1d0610d9b8ab4