i am using below but it does not work.

<style name="SearchTheme" parent="@style/Theme.Leanback.Browse">
    <item name="rowHeaderDockStyle">@style/RowHeaderDock</item>
    <item name="rowHorizontalGridStyle">@style/HorizentalGridStyle</item>
</style>

<style name="RowHeaderDock">
    <item name="android:paddingStart">0dp</item>
</style>
<style name="HorizentalGridStyle" parent="Widget.Leanback.Row.HorizontalGridView">
    <item name="android:paddingStart">0dp</item>
</style>