Add --checkout-only option to ojluni_refresh_files script

So no commit is created when the option is provided.
It's useful for preview of the files before creating commits
or detaching the git history from the upstream.

Test: ojluni_refresh_files
Test: ojluni_refresh_files --checkout-only
Change-Id: Ibe8633812920eb71b7fb2065271f905da781cca9
1 file changed
tree: 2947f901a916880bfec9beccf8f68241815596e7
  1. ojluni/
  2. tools/
  3. EXPECTED_UPSTREAM