I've had a look into creating the "stack" of shapes that you are looking for using "drawable" XML, but the padding/height values seem to be ignored.
There are two possible workarounds that I can think of:
Create a class that implements Drawable
for the background and the progress and draw the custom colours/gradients yourself.
-OR-
Create a PNG of the background (on the right) and progress (on the left) from your mockups. About 30px wide should be fine (if you make them 1px wide, it will be put more pressure on the layout because it has to be repeated more times). Throw those in res/drawable/ and then load them into your styles using <bitmap>
:
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@android:id/background">
<bitmap android:src="@drawable/scroll_bg" />
</item>
<item android:id="@android:id/progress">
<clip>
<bitmap android:src="@drawable/scroll_progress" />
</clip>
</item>
</layer-list>