如何显示tablayout的滚动条？

<style name="TabLayoutScrollBar">
    <item name="android:scrollbarThumbVertical">@drawable/custom_scrollbar_thumb</item>
    <item name="android:scrollbarTrackVertical">@drawable/custom_scrollbar_track</item>
</style>

<com.google.android.material.tabs.TabLayout
    android:id="@+id/tabLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    style="@style/TabLayoutScrollBar"
    app:tabMode="scrollable" />

<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#FF0000" /> <!-- 设置滚动条拇指的颜色 -->
    <size android:width="8dp" /> <!-- 设置滚动条拇指的宽度 -->
</shape>

<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#CCCCCC" /> <!-- 设置滚动条轨道的颜色 -->
</shape>