sometimes gets stuck on unpacking system

[sshane]

if it really is in progress and not stuck, it shouldn't say 100%

edit: left here for ~10 minutes, no change in progress

edit: oh I see the progress is for the current step, yeah seems stuck somewhere

https://github.com/commaai/flash/assets/25857203/114045c2-03b5-4b52-b7b5-80bf7eb5a386

edit: hmm, after refreshing and recording that clip above, it passed the unpacking step after maybe 30 seconds at 100% and is now flashing properly

[incognitojam]

will add a test for this once the new images are in

[adeebshihadeh]

This has been partially rewritten.