Code cleanup using AndroidStudio's analyze feature.

src/main/java/de/dennisguse/opentracks/TrackDeleteActivity.java

@@ -78,6 +78,12 @@ public class TrackDeleteActivity extends AbstractActivity {
         deleteThread.interrupt();
     }
 
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        viewBinding = null;
+    }
+
     @Override
     protected View getRootView() {
         viewBinding = TrackDeleteBinding.inflate(getLayoutInflater());