This would not be exactly the same as your app but you'll get the idea. The solution is based on AndroidViewClient/culebra.
I'm using the Progress dialog example from API Demos so it will be easily reproducible by anyone.
When you press API Demos -> App/Alert Dialogs you obtain
then you can run culebra to automatically generate a test script
$ culebra -VC -t on -r -o myscript.py
edit the script to remove the unneeded Views and loop while progress is being incremented
# generated script lines removed for clarity
while True:
vc.dump(window='-1')
no_id15 = vc.findViewWithTextOrRaise(re.compile('\d+/100'))
print no_id15.getText()
the output would be
Connecting to a device with serialno=.* with a timeout of 60 secs...
Connected to device with serialno=.*
Actual device serialno=emulator-5554
21/100
24/100
26/100
28/100
...
98/100
100/100