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/init.cpp b/init/init.cpp
index 95f272b..79623c3 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -110,12 +110,15 @@
         if (!parser.ParseConfig("/system/etc/init")) {
             late_import_paths.emplace_back("/system/etc/init");
         }
-        if (!parser.ParseConfig("/vendor/etc/init")) {
-            late_import_paths.emplace_back("/vendor/etc/init");
+        if (!parser.ParseConfig("/product/etc/init")) {
+            late_import_paths.emplace_back("/product/etc/init");
         }
         if (!parser.ParseConfig("/odm/etc/init")) {
             late_import_paths.emplace_back("/odm/etc/init");
         }
+        if (!parser.ParseConfig("/vendor/etc/init")) {
+            late_import_paths.emplace_back("/vendor/etc/init");
+        }
     } else {
         parser.ParseConfig(bootscript);
     }