Android ActionMenuView如何设置菜单项图标的大小

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/menu_item"
        android:title="Menu Item"
        app:actionLayout="@layout/menu_item_layout" />
</menu>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <ImageView
        android:layout_width="24dp"
        android:layout_height="24dp"
        android:src="@drawable/menu_icon" />

</LinearLayout>

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_custom, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    if (id == R.id.menu_item) {
        // 菜单项点击事件处理
        return true;
    }
    return super.onOptionsItemSelected(item);
}