cardview set padding not working
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="match_parent"
android:layout_height="200dp"
card_view:cardCornerRadius="2dp"
card_view:contentPaddingLeft="20dp"
card_view:contentPaddingRight="@dimen/activity_horizontal_margin"
card_view:contentPaddingTop="20dp"
card_view:contentPaddingBottom="@dimen/activity_vertical_margin">
<TextView
android:id="@+id/info_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello World!"/>
</android.support.v7.widget.CardView>