Can't get rounded corners for my layer-list drawable

Question

I have made a button drawable that consists of a gradient shape and a solid shape, both in a layer-list like this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:height="25dp">
        <shape android:shape="rectangle" >
            <gradient
                android:angle="90"
                android:startColor="@color/greyDark1"
                android:endColor="@color/greyDark2"/>
        </shape>
    </item>
    <item android:top="25dp" android:height="25dp">
        <shape android:shape="rectangle" >
            <solid android:color="@color/black" />
        </shape>
    </item>
</layer-list>

But I can't get the corners right. I need rounded corners around the entire shape, but not on the inside (so topRight and topLeft op the top half and bottomRight and bottomLeft for the bottom half).

If I set both halves with <corners android:radius="8dp"> the bottom corners of the top half and the top corners of the bottom half are rounded too, and that's not what I want.

If I set <corners android:topRightRadius="8dp" android:topLeftRadius"8dp"> for the top half and <corners android:bottomRightRadius="8dp" android:bottomLeftRadius"8dp"> for the bottom half the top half would be the full size of the drawable making the gradient not working properly and the bottom corners are that same color too.

Here is an image of what I'm trying to accomplish:

Does someone know a solution to this?

EDIT:

I have gotten some answers and I'm thankful for that, but sadly enough they don't seem to work.

The answers I got from bofredo and Bhuvnesh Chasta resulted in something like this:

And the answer I got from curiousMind looks pretty nice, but isn't what I'm aiming for:

FINAL EDIT:

I have discussed this problem with someone I was working with and we both agree that it isn't that important to have it look like this, so we went with a solid color.

I still want to thank everybody who helped, all the current answers will get an upvote and I will accept the answer from waqaslam because he came very close to what I wanted.

Answer 1

I think that's the closest you can reach to your desired drawable using xml.

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
    <shape android:shape="rectangle">
        <corners android:radius="2dp"/>
        <gradient android:startColor="#4e4e4e" android:centerColor="#626262" android:endColor="@android:color/transparent" android:angle="270" />
    </shape>
</item>
<item>
    <shape android:shape="rectangle">
        <corners android:radius="2dp"/>
        <gradient android:startColor="@android:color/transparent" android:centerColor="#4c4c4c" android:endColor="#1c1c1c" android:angle="270" />
    </shape>
</item>

Perhaps you should use 9-patch drawable to get the exact effect.