RelativeLayout background overlap availability

I have a 9-patch drawable (date_time). And I want to position this resource over the content of the Relative Layout, so all child views should be drawn on top of this image. Here is the xml Layout:

<RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="23dp"
            android:layout_below="@id/tv_map_address"
            android:layout_marginTop="11dp"
            android:layout_marginBottom="12dp"
            android:background="@drawable/date_time">

            <ImageView
                android:id="@+id/iv_map_distance"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_centerVertical="true"
                android:src="@drawable/ic_map_distance"/>

            <TextView
                android:id="@+id/tv_map_distance"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_toRightOf="@id/iv_map_distance"
                android:layout_centerVertical="true"
                android:textColor="@color/white"
                android:textSize="11sp"
                android:text="2,7 "
                fontPath="fonts/Roboto-Medium.ttf"/>

            <ImageView
                android:id="@+id/iv_map_path"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_toRightOf="@id/tv_map_distance"
                android:layout_centerVertical="true"
                android:src="@drawable/ic_map_path"/>

            <TextView
                android:id="@+id/tv_map_path"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_toRightOf="@id/iv_map_path"
                android:layout_centerVertical="true"
                android:textColor="@color/white"
                android:textSize="11sp"
                android:text="3,2 "
                fontPath="fonts/Roboto-Medium.ttf"/>

        </RelativeLayout>

      

        
        
        
      

    

But somehow this background overlaps all child content. This shows what's going on.

But if I replace

android:background="@drawable/date_time"

      

        
        
        
      

    

to

android:background="#0000FF"

      

        
        
        
      

    

Everything is fine and the result is as follows:

Can you explain to me what I am doing wrong?

Update: Here is my version with 9 patches.