Rename product_services to system_ext

Bug: 134359158
Test: build and boot
Change-Id: I2ea21a0e528bdbab7d2479b48c73e7f2274ecca5
diff --git a/updater/build_info.cpp b/updater/build_info.cpp
index 8e87bd3..3072aab 100644
--- a/updater/build_info.cpp
+++ b/updater/build_info.cpp
@@ -79,7 +79,7 @@
     "ro.product.name"
   };
   const std::vector<std::string> source_order = {
-    "product", "product_services", "odm", "vendor", "system",
+    "product", "odm", "vendor", "system_ext", "system",
   };
   if (ro_product_props.find(key) != ro_product_props.end()) {
     std::string_view key_suffix(key);