Merge "Warn on `repo upload` if you're not uploading to AOSP master."

clang_format = --commit ${PREUPLOAD_COMMIT} --style file --extensions c,h,cc,cpp

[Hook Scripts]

aosp_hook = ${REPO_ROOT}/frameworks/base/tools/aosp/aosp_sha.sh ${PREUPLOAD_COMMIT} "."

checkstyle_hook = ${REPO_ROOT}/prebuilts/checkstyle/checkstyle.py --sha ${PREUPLOAD_COMMIT}

                  --file_whitelist tools/ updater_sample/