CardView 去除内边距

 <androidx.cardview.widget.CardView
        android:id="@+id/cv_media_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="@dimen/dp_18"
        android:layout_marginTop="@dimen/dp_16"
        app:cardCornerRadius="@dimen/dp_4"
        app:cardPreventCornerOverlap="true"
        app:cardUseCompatPadding="false"
        app:cardElevation="0dp"
        app:cardBackgroundColor="@color/transparent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.appcompat.widget.AppCompatImageView
            android:id="@+id/iv_media_icon"
            android:layout_width="@dimen/dp_42"
            android:layout_height="@dimen/dp_42"
            android:scaleType="centerCrop"
            tools:src="@android:drawable/btn_dialog" />
    </androidx.cardview.widget.CardView>