While you have android:updatePeriodMillis set to 20 seconds, the minimum actual time is 30 minutes. So, if you have not been waiting 30 minutes to see if there is an update during your testing, you will need to wait a bit longer.
While you have `android:updatePeriodMillis` set to 20 seconds, the minimum actual time is 30 minutes. So, if you have not been waiting 30 minutes to see if there is an update during your testing, you will need to wait a bit longer.