Updated StatsPerUidLogger device wide component power consumed reporting

- updated powerMah to float conversion

Flag: com.android.server.power.optimization.add_battery_usage_stats_slice_atom
Bug: 368271881
Test: atest android.cts.statsdatom.batterystats.BatteryUsageStatsTests#testBatteryUsageStatsPerUid
Change-Id: I8348940e0ea65c21a8019240043f77238c0a93c9