Use battery unplugging event to compute the full charge start time on

Pixel devices.

Test: make RunSettingsRoboTests + manual
Bug: 256124406
Change-Id: I80b33db6e25ac0c693c50ddf93b6343c0fea942f

src/com/android/settings/fuelgauge/PowerUsageFeatureProviderImpl.java

@@ -147,6 +147,11 @@ public class PowerUsageFeatureProviderImpl implements PowerUsageFeatureProvider
         return null;
     }
 
+    @Override
+    public String getFullChargeIntentAction() {
+        return Intent.ACTION_BATTERY_LEVEL_CHANGED;
+    }
+
     @Override
     public boolean isExtraDefend() {
         return false;