This change includes: 1. Mark groupedBy*() deprecated and throw after android U. 2. Modify map() to mapKeysNotNull(). 3. rename clearInterfaces to withoutInterfaces and refactoring. 4. Modify tests accordingly. Test: atest FrameworksNetTests:android.net.connectivity.android.net.NetworkStatsTest Fix: 296149902 Fix: 296150018 Change-Id: I5d97422ba957a212c0c5fbc1eee3f8b174343348