Rename statistics activity layout

Author: grepx

todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/MainActivity.java

@@ -47,7 +47,7 @@ public class MainActivity extends AppCompatActivity {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        setContentView(R.layout.statistics_act);
+        setContentView(R.layout.main_act);
 
         // Set up the toolbar.
         Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);