How to add blurry to drawable?

[passmanagerapp]

I display a drawable in Mapbox. What I want is just to apply blurry to a drawable.
`

<item android:drawable="@drawable/text_back">
</item>
<item
    >
    <shape android:shape="rectangle">
        <solid android:color="#99FFFFFF" />
        <corners android:radius="@dimen/text_back_radius_def"
            android:bottomRightRadius="33dp"/>
    </shape>
</item>

`