Set the alpha to 1 when overview button is focused.

            android:valueType="floatType" />

    </item>

    <item android:state_focused="true">

        <objectAnimator

            android:duration="@android:integer/config_shortAnimTime"

            android:propertyName="alpha"

            android:valueTo="0.5"

            android:valueType="floatType" />

    </item>

    <item>

        <objectAnimator

            android:duration="@android:integer/config_shortAnimTime"