test: satisfy STEP-117 strict NDK C++ warning checks

test/renderer/retained_underlay_cache.test.cpp

@@ -93,6 +93,7 @@ std::shared_ptr<UpdateParameters> step117PlacementParameters(TimePoint now,
         .prefetchZoomDelta = 0,
         .stillImageRequest = false,
         .crossSourceCollisions = true,
+        .retainedUnderlayState = {},
     });
 }
 } // namespace