Add measured camera stats to BatteryUsageStats

Implement POWER_MODEL_ENERGY_CONSUMPTION in CameraPowerCalculator by
using the camera energy consumption from BatteryStatsImpl.

Per-UID stats are will be supported in a follow-up change.

Bug: 258319905
Test: atest BatteryStatsTests
Test: Use the camera while not charging, observe usage in Battery Stats
Change-Id: I9df6c2d2300fdebc516d7b674c311e9be36b0d44