[mob][photos] Don't show empty faces in debug

mobile/lib/ui/viewer/file_details/face_widget.dart

@@ -233,6 +233,12 @@ class _FaceWidgetState extends State<FaceWidget> {
                       style: Theme.of(context).textTheme.bodySmall,
                       maxLines: 1,
                     ),
+                  if (kDebugMode && widget.face.score < 0.75)
+                    Text(
+                      '[Debug only]',
+                      style: Theme.of(context).textTheme.bodySmall,
+                      maxLines: 1,
+                    ),
                   // if (kDebugMode)
                   //   if (highlight)
                   //     const Text(

mobile/lib/ui/viewer/file_details/faces_item_widget.dart

@@ -79,6 +79,8 @@ class _FacesItemWidgetState extends State<FacesItemWidget> {
       // Remove faces with low scores
       if (!kDebugMode) {
         faces.removeWhere((face) => (face.score < 0.75));
+      } else {
+        faces.removeWhere((face) => (face.score < 0.5));
       }
 
       if (faces.isEmpty) {