Run "insane" network jobs when charging + unmetered.

When we're charging and on an unmetered network, run jobs that we
calcluate won't complete within the max execution time due to the
network speed, just so they have a chance of running.

Also update documentation to guide to only providing size of
non-interruptible transfers.

Bug: 188429037
Test: Run `m offline-sdk-docs` and check site at out/target/common/docs/offline-sdk/reference/android/app/job/JobInfo.html
Test: atest FrameworksMockingServicesTests:ConnectivityControllerTest
Change-Id: Ic69e85a7e0eae51b3dd3ea89bd00255a734c1472