I'm turning off our current FTL API 26 device testing due to #129873. While we could re-enable it once whatever the FTL-side issue is resolved (although it's worth noting that this isn't the first time, so it could well happen yet again), we are actively working on bringing up LUCI emulator tests, so a better route if that doesn't get stuck would be to switch legacy testing over to emulators, and only do device testing (which is inherently more costly, and almost certainly slower and flakier) on a single device.

@reidbaker FYI about the temporarily reduced coverage, and the plan to shift away from testing multiple OSes on actual devices (absent any objections)