Hardcode bottom nav height (fixes #5698)

This shouldn't be an issue since the spec defines the height to always be 56dp anyway.

app/src/main/res/layout/main_activity.xml

@@ -78,7 +78,7 @@
     <com.google.android.material.bottomnavigation.BottomNavigationView
         android:id="@+id/bottom_nav"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content"
+        android:layout_height="56dp"
         android:layout_gravity="bottom"
         android:clickable="true"
         app:layout_insetEdge="bottom"