Ensure `adbd` has root permissions before pushing files to ART's chroot dir.

Run `adb root` at the beginning of `tools/buildbot-sync.sh` to make
sure `adb` is able to push files to ART's chroot testing
environment. This is just a precaution, as we expect
`tools/buildbot-setup-device.sh` to perform this action beforehand.

Test: art/tools/buildbot-build.sh --target \
        && art/tools/buildbot-setup-device.sh
        && art/tools/buildbot-sync.sh
Bug: 34729697

Change-Id: I14b072e43cc0b004aacf00488a7ca313227e038d
1 file changed