How to hide or add menu items for Flavor?

I have an app that has 3 different flavors, full, part1 and part2.

All different flavors have different package names, so I can ship them as different apps.

Now I want that only part1 gets a menu item called Reload. The other 2 flavors shouldn't have this menu item. Is this possible?

I tried the following with the menu resources:

app
|
+-src
  |
  +-full
  |
  +-main
  | |
  | +-res
  |   |
  |   +-menu
  |     |
  |     +-main_activity.xml
  |
  +-part1
  | |
  | +-res
  |   |
  |   +-menu
  |     |
  |     +-main_activity.xml
  |
  +-part2

Where main_activity.xml for part1 is:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/action_reload"
        android:icon="@drawable/ic_reload"
        android:title="@string/action_reload"
        app:showAsAction="always"/>
</menu>

And main_activity.xml for main is:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto">
</menu>

However, if I build the app in any other build variant than part1, I get a compilation error in my MainActivity where I need to react to the menu selection:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.action_reload: // Compile error: This item is not available
            // TODO reload
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

It's quite obvious why that is. But do you have any suggestion what the solution is to customize menus for different build flavors?

Create a MainActivity in the main source folder where you handle the normal common code. Create another MainActivity in the part1 source folder where you override onOptionsItemSelected where it's not a problem to have references to R.id.action_reload. That should work.