Allow users to specify list of files/path to google-java-format

Bug: 69068870
Test: Ran "repo upload" and verified that google-java-format runs on all
      modified files when a list of files/path is not specified.
Test: Ran "repo upload" and verified that google-java-format runs on all
      modified files from a list of files/path.
Change-Id: Ib07c9fa81ffbcf7ef38feaf6ea40b321c701f998