Remove dial button's fade effect

<!-- Background resource for call button in the various dialpads.

     Almost a copy from framework's item_background_holo_dark.xml, but has different pressed effect

  -->

<selector xmlns:android="http://schemas.android.com/apk/res/android"

          android:exitFadeDuration="@android:integer/config_mediumAnimTime">

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_window_focused="false" android:drawable="@android:color/transparent" />