Add .gitmodules file.

Bug: 1421776
Change-Id: I6890eda6f1c9b40c27343a359b1a5dd3027276c7
Reviewed-on: https://chromium-review.googlesource.com/c/android_tools/+/4312583
Reviewed-by: John Budorick <jbudorick@chromium.org>
2 files changed