SearchView和ListView搭配使用时,搜索之后出现的那个黑色的提示怎么去掉

SearchView和ListView搭配使用时,搜索之后出现的那个黑色的提示怎么去掉,求指导

布局文件如下:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.SearchNameActivity"
    android:orientation="vertical"
    android:layout_margin="10dp">
    <LinearLayout
        android:layout_height="40dp"
        android:layout_width="match_parent"
        android:background="@drawable/bg_linearlayout"
        android:orientation="horizontal">
        <Button
            android:id="@+id/backBth"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/back"
            android:visibility="gone"
            android:contentDescription="@string/hint" />
        <SearchView
            android:id="@+id/searchName"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="8"
            android:iconifiedByDefault="false"
            android:queryHint="@string/search"
            android:imeOptions="actionSearch"
            android:inputType="text"/>
    </LinearLayout>
    <ListView
        android:id="@+id/listName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <TextView
        android:id="@+id/noSearchResult"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:visibility="gone"
        android:layout_gravity="center"
        android:textSize="22sp"/>
</LinearLayout>

activity文件如下:

class SearchNameActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_search_name)
        //植物名称数据集合
        val mainPlantNameList: ArrayList<String> = ArrayList<String>()
        mainPlantNameList.addAll(PlantData.africanPlantNameList)
        mainPlantNameList.addAll(PlantData.americanPlantNameList)
        mainPlantNameList.addAll(PlantData.asiaticPlantNameList)
        mainPlantNameList.addAll(PlantData.europeanPlantNameList)
        mainPlantNameList.addAll(PlantData.oceaniaPlantNameList)
        mainPlantNameList.addAll(PlantData.otherPlantNameList)
        //给listView设置适配器
        listName.adapter = ArrayAdapter(this, android.R.layout.simple_expandable_list_item_1, mainPlantNameList)
        listName.isTextFilterEnabled = true
        searchName.suggestionsAdapter = null
        //设置文本监听
        searchName.setOnQueryTextListener(object : SearchView.OnQueryTextListener{
            override fun onQueryTextSubmit(query: String): Boolean {
                searchName.setQuery("", false)
                searchName.clearFocus()
                return true
            }

            override fun onQueryTextChange(newText: String): Boolean {
                if (mainPlantNameList.contains(newText)) {
                    listName.setFilterText(newText)
                } else {
                    listName.visibility = View.GONE
                    noSearchResult.visibility = View.VISIBLE
                    noSearchResult.text="该植物不是中国农林主要外来植物,不需要进行信息登记."
                    backBth.visibility = View.VISIBLE
                    backBth.setOnClickListener {
                        val intent = Intent(this@SearchNameActivity, MainActivity::class.java)
                        startActivity(intent)
                        finish()
                    }
                }
                return true
            }
        })
        listName.setOnItemClickListener { parent, view, position, id ->
            val selectedResult = listName.adapter.getItem(position) as String
            val intent = Intent(this, MainInforActivity::class.java)
            intent.putExtra("selectedResult", selectedResult)
            startActivity(intent)
            finish()
        }
    }
}