Test: local run
Change-Id: Id22f9faee9241eeb1a77f7cbd79fe27f73c0350a

If the version in METADATA is a commit (sha1), the tool will try to
download the latest master from github, instead of latest release.

Test: update METADATA of androidplot and try to update.
Change-Id: Id12b797ca152f11d16c4d06c44e30758bec40f24

Test: NA
Change-Id: If5d8d0ea5903e1cf4c2cb62dd3802fb3706458cb

If the upstream is GIT and version is not a hash, updater will try to
list upstream tags to find a newer version. And suggest to merge from
that tag.

Change-Id: I34651815c761c78fd0485df0a84adc086a810e9e
Test: Change googletest/METADATA to follow upstream releases. And run updater.

Bug: 109748616
Test: https://android-review.googlesource.com/c/platform/external/kotlinc/+/699886
Change-Id: I1c28aa256bca6ee5be1ea15f295c5e0fa63526d1