Move to a separate branch of gradle prebuilts

This will allow dackka to do its own upgrades without being affected
by androidx-main changes.

Change-Id: I640928017b7260c68ba445eaa54e4605c0471bd2
Test: None
1 file changed
tree: 644177a6b859d646bb03e2b02e3db1251e902e74
  1. default.xml