Add new color: accent with 60% opacity.

     overlaying new theme colors. -->

<resources>

    <color name="button_normal_device_default_dark">@color/btn_default_material_dark</color>

    <!-- Use the same value as for accent_device_default_dark but start with #99,

         i.e. 60% opacity -->

    <color name="accent_device_default_dark_60_percent_opacity">#995E97f6</color>

</resources>