Merge "DO NOT MERGE Handle back button for notification panel" into rvc-qpr-dev

packages/CarSystemUI/src/com/android/systemui/car/notification/NotificationPanelViewController.java

@@ -28,6 +28,7 @@ import android.os.IBinder;
 import android.os.RemoteException;
 import android.util.Log;
 import android.view.GestureDetector;
+import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
 import android.view.View;
@@ -245,6 +246,17 @@ public class NotificationPanelViewController extends OverlayPanelViewController
         mNotificationView = (CarNotificationView) LayoutInflater.from(mContext).inflate(
                 R.layout.notification_center_activity, container,
                 /* attachToRoot= */ false);
+        mNotificationView.setKeyEventHandler(
+                event -> {
+                    if (event.getKeyCode() != KeyEvent.KEYCODE_BACK) {
+                        return false;
+                    }
+
+                    if (event.getAction() == KeyEvent.ACTION_UP && isPanelExpanded()) {
+                        toggle();
+                    }
+                    return true;
+                });
 
         container.addView(mNotificationView);
         onNotificationViewInflated();