Add new DeviceDefault.Light.Voice theme.

Settings uses it now and there's an equivalent Material theme
that was being used.

Bug: 30140567
Change-Id: Ibbf8a313094eee3c3b409479d9fc984005c5032c
diff --git a/core/res/res/values/themes_device_defaults.xml b/core/res/res/values/themes_device_defaults.xml
index 50e588d..0e98ade 100644
--- a/core/res/res/values/themes_device_defaults.xml
+++ b/core/res/res/values/themes_device_defaults.xml
@@ -724,6 +724,12 @@
         <item name="colorAccent">@color/accent_device_default_light</item>
     </style>
 
+    <style name="Theme.DeviceDefault.Light.Voice" parent="Theme.Material.Light.Voice">
+        <!-- Color palette -->
+        <item name="colorPrimary">@color/primary_device_default_light</item>
+        <item name="colorPrimaryDark">@color/primary_dark_device_default_light</item>
+        <item name="colorAccent">@color/accent_device_default_light</item>
+    </style>
 
     <!-- DeviceDefault theme for a window that should look like the Settings app.  -->
     <style name="Theme.DeviceDefault.Settings" parent="Theme.Material.Settings">