Merge "Add unit test for NetworkStatsSubscriptionsMonitor" into rvc-dev am: 32f8a56636 am: ea43b62474

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11788484

Change-Id: I0e5b064f0633474c5200ecf4620540e883af5d0b