Revert (Partially) "Remove obsolete Android versions from packager."

This reverts commit 2ad17d4e1bf3f4012fdc39fd1866ec1f3a7c3a61.

Reason for revert: We need new revisions for system_image on old android version

Original change's description:
> Remove obsolete Android versions from packager.
>
> Remove packages for SDK 28 and earlier as we've been using SDK 29 for
> some time already. Keep SDK 29 for now until the SDK 30 roll is
> successfully completed.
>
> Change-Id: Ib15bd1330c95835e61df416192620048c45e5a22
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2305011
> Reviewed-by: Andrew Grieve <agrieve@chromium.org>
> Reviewed-by: Garrett Beaty <gbeaty@chromium.org>
> Commit-Queue: Richard Coles <torne@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#789629}

Bug: 1217768
Change-Id: I34ad9b6066cce8b63b67d9ca25d24c6e0761c33c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2946141
Auto-Submit: Haiyang Pan <hypan@google.com>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Garrett Beaty <gbeaty@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#890548}
NOKEYCHECK=True
GitOrigin-RevId: cb8ba5a1fa45e6217d31df0f336926247f74a81f