Change the behavior of the hardware menu button when it is present to show/hide the toolbar overflow menu - From http://stackoverflow.com/questions/27362030/toolbar-overflow-menu-button-always-showing

show_hide_overflow_menu_with_toolbar.java

@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
    
    if (keyCode == KeyEvent.KEYCODE_MENU) {
        
        if (mToolbar.isOverflowMenuShowing()) {
            
            mToolbar.hideOverflowMenu();
        } 
        else {
            mToolbar.showOverflowMenu();
        }
        
        return true;
    }
    
    return super.onKeyUp(keyCode, event);
}