OmniGears: notification lights - support for devices without multi-color led

See also http://jira.omnirom.org/browse/UIREVIEW-4

For devices that dont have a multi-color led the color picker
dialog in notification lights makes not much sense

This creates an adapted dialog which supports a list of colors
that can be provided in the device overlay

To enable:
<bool name="config_has_multi_color_led" translatable="false">false</bool>

Default color list:
<string-array name="entries_led_colors" translatable="false">
<item>@string/led_color_green</item>
<item>@string/led_color_red</item>
</string-array>

<string-array name="values_led_colors" translatable="false">
<item>#FF00FF00</item>
<item>#FFFF0000</item>
</string-array>

PS2:
whitespace cleanup

PS3:
remove unneded separator line

Change-Id: I783cfcc42b1753148da31d521e09c134fab4311a