Simplify navigation in BatteryStatsViewer

Bug: 185952656
Test: mp :BatteryStatsViewer && adb shell am start -n com.android.frameworks.core.batterystatsviewer/.BatteryConsumerPickerActivity
Change-Id: I5c8958411c2436a0d1e8fafb79759b9e40d81b18
3 files changed