Add a new field elapsed_time_millis into Settings' atom

- Add a new field elapsed_time_millis to keep the elapsed time
  since setup wizard finished.

Fixes: 260660970
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.core
Change-Id: I28d13c4987ae1e4ef12eaff27e26a5121cf8093b

src/com/android/settings/fuelgauge/batteryusage/BootBroadcastReceiver.java

@@ -23,6 +23,8 @@ import android.os.Handler;
 import android.os.Looper;
 import android.util.Log;
 
+import com.android.settings.core.instrumentation.ElapsedTimeUtils;
+
 import java.time.Duration;
 
 /** Receives broadcasts to start or stop the periodic fetching job. */
@@ -77,6 +79,8 @@ public final class BootBroadcastReceiver extends BroadcastReceiver {
             recheckIntent.setClass(context, BootBroadcastReceiver.class);
             mHandler.postDelayed(() -> context.sendBroadcast(recheckIntent),
                     RESCHEDULE_FOR_BOOT_ACTION);
+        } else if (ACTION_SETUP_WIZARD_FINISHED.equals(action)) {
+            ElapsedTimeUtils.storeSuwFinishedTimestamp(context, System.currentTimeMillis());
         }
     }