Android: fix a crash on app resume when native views are displayed.

modules/juce_core/native/java/JuceAppActivity.java

@@ -222,9 +222,12 @@ public class JuceAppActivity   extends $$JuceAppActivityBaseClass$$
         super.onResume();
         resumeApp();
 
-        // Ensure that navigation/status bar visibility is correctly restored.
-        for (int i = 0; i < viewHolder.getChildCount(); ++i)
-            ((ComponentPeerView) viewHolder.getChildAt (i)).appResumed();
+        // Ensure that navigation/status bar visibility is correctly restored.
+        for (int i = 0; i < viewHolder.getChildCount(); ++i)
+        {
+            if (viewHolder.getChildAt (i) instanceof ComponentPeerView)
+                ((ComponentPeerView) viewHolder.getChildAt (i)).appResumed();
+        }
     }
 
     @Override