Support /product partition

This CL will enable reading /product/build.prop and add product paths
into ld.config.txt.in.

Bug: 64195575
Test: tested with 'PRODUCT_PRODUCT_PROPERTIES := ro.product.abc=abc' on
sailfish

Change-Id: Ie996def20e25dc1afe0c74af2096af844934b2dc
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 0cb9e63..fa28fa3 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -641,6 +641,7 @@
             load_properties_from_file("/default.prop", NULL);
         }
     }
+    load_properties_from_file("/product/build.prop", NULL);
     load_properties_from_file("/odm/default.prop", NULL);
     load_properties_from_file("/vendor/default.prop", NULL);