Fix non-bot mode sharding on Android and disable elsewhere. There is no need to apply sharding internally on Android, since it is done on the host, except when listing tests. And on other platforms sharding in non-bot mode is not useful. Patch authored by Yuly Novikov (ynovikov@chromium.org) Bug: angleproject:5417 Change-Id: Iddc0e1a38fb514617dce527acc99d0dce85ca177 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3399250 Reviewed-by: Yuly Novikov <ynovikov@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>