This looks like fallout from the luci migration.

The builder in question is now https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Android%20Builder%20(dbg)

This builder was migrated, and I took all of its testers offline, so I also removed this builder from buildbot since it wouldn't be doing any useful work (the luci version is running correctly).

Because the tests weren't swarmed, devices possibly require some sort of special configuration (so it wasn't possible to mirror), and the builder was set up on chromium.fyi, I opted to take them offline.

But the original bug is asking about Android Builder (dbg) specifically (And not the downstream bots), which has moved to LUCI as per comment #2, so I'll mark this ask fixed.