Unable to set value for flexMillis in Android.

[jeberhardt]

On Android API level 24+, there is a property in the JobInfo object called flexMillis. This affects when a periodic task will be executed from the interval time.

Currently, BGTask calls setPeriodic with the same values for intervalMillis and flexMillis:

builder.setPeriodic(interval, interval);

This means, if I want a really long interval period, like 4 hours, then the flex window will also be 4 hours, meaning the job will run anywhere between 4-8 hours. The longer the interval, the longer the flex window.

It would be great if the flexMillis value could be passed with the config to prevent an inadvertently longer flex window.