使用navhost时无法更改工具栏返回图标

<fragment
    android:id="@+id/destination_fragment"
    android:name="com.example.DestinationFragment"
    android:label="Destination"
    tools:layout="@layout/fragment_destination">
    <action
        android:id="@+id/action_destination_to_home"
        app:destination="@id/home_fragment"
        app:popUpTo="@id/home_fragment"
        app:popUpToInclusive="true" />
    <action
        android:id="@+id/action_destination_to_settings"
        app:destination="@id/settings_fragment" />
</fragment>

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/custom_toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <!-- 添加其他视图元素 -->

</androidx.constraintlayout.widget.ConstraintLayout>

class DestinationFragment : Fragment() {

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        val view = inflater.inflate(R.layout.fragment_destination, container, false)
        val toolbar = view.findViewById<Toolbar>(R.id.custom_toolbar)
        (activity as AppCompatActivity).setSupportActionBar(toolbar)
        return view
    }

    // 其他相关代码

}