omni: add lato font overlay

add file fonts_customization.xml to allow using
fonts in /product/fonts

Change-Id: Icee8715f9960ac7b27daeebb393d4b28b1848df6
diff --git a/config/packages.mk b/config/packages.mk
index 13f7e21..f9f171d 100644
--- a/config/packages.mk
+++ b/config/packages.mk
@@ -74,3 +74,5 @@
 PRODUCT_PACKAGES_ENG += \
     bash \
     su
+
+$(call inherit-product-if-exists, external/google-fonts/lato/fonts.mk)