ChatMessageView with no content padding not rounding borders

[MrBrightside29]

When setting the content_padding xml property to 0dp the view does not round the corners.
In my case I'm using the ChatMessageView to show an ImageView and I'd like to not show any background around the ImageView. Here is my xml:

<me.himanshusoni.chatmessageview.ChatMessageView xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:cmv_arrowGravity="start"
        app:cmv_arrowMargin="3dp"
        app:cmv_arrowPosition="right"
        app:cmv_backgroundColor="@color/md_grey_300"
        app:cmv_backgroundColorPressed="@color/md_pink_50"
        app:cmv_contentPadding="0dp"
        app:cmv_cornerRadius="3dp"
        app:cmv_showArrow="true">

        <FrameLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"            
            android:orientation="vertical">

            <ImageView
                android:id="@+id/imageView"
                android:layout_width="200dp"
                android:layout_height="180dp"
                android:adjustViewBounds="true"
                android:scaleType="centerCrop" />

            <TextView
                android:id="@+id/tVtimestamp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom|end"
                android:fontFamily="sans-serif"
                android:padding="4dp"
                android:text="14:30"
                android:textAppearance="?android:attr/textAppearanceSmall"
                android:textColor="@color/md_white_1000"
                android:textSize="12sp"
                android:shadowColor="#8000"
                android:shadowDx="0"
                android:shadowDy="2"
                android:shadowRadius="2"/>

        </FrameLayout>
    </me.himanshusoni.chatmessageview.ChatMessageView>

And this is what shows in app: