Consider overlay in system_ext as system's

When there is overlay package in system_ext, turn on POLICY_SYSTEM_PARTITION.
In other words, overlay pacakge in /system_ext is considered as system's one

Test: mv vendor/overlay/framework-res__auto_generated_rro.apk system_ext/overlay
      and then check if it works properly.
Bug: 136715327

Change-Id: Ib225368eae41203a8630f4310d26e9cf1afa706a
diff --git a/core/jni/android_util_AssetManager.cpp b/core/jni/android_util_AssetManager.cpp
index d6d9391..bf4ffc7 100644
--- a/core/jni/android_util_AssetManager.cpp
+++ b/core/jni/android_util_AssetManager.cpp
@@ -161,7 +161,7 @@
       }
 
       // Generic idmap parameters
-      const char* argv[10];
+      const char* argv[11];
       int argc = 0;
       struct stat st;
 
@@ -193,8 +193,8 @@
         argv[argc++] = AssetManager::PRODUCT_OVERLAY_DIR;
       }
 
-      if (stat(AssetManager::PRODUCT_SERVICES_OVERLAY_DIR, &st) == 0) {
-        argv[argc++] = AssetManager::PRODUCT_SERVICES_OVERLAY_DIR;
+      if (stat(AssetManager::SYSTEM_EXT_OVERLAY_DIR, &st) == 0) {
+        argv[argc++] = AssetManager::SYSTEM_EXT_OVERLAY_DIR;
       }
 
       if (stat(AssetManager::ODM_OVERLAY_DIR, &st) == 0) {
@@ -235,8 +235,8 @@
     input_dirs.push_back(AssetManager::PRODUCT_OVERLAY_DIR);
   }
 
-  if (stat(AssetManager::PRODUCT_SERVICES_OVERLAY_DIR, &st) == 0) {
-    input_dirs.push_back(AssetManager::PRODUCT_SERVICES_OVERLAY_DIR);
+  if (stat(AssetManager::SYSTEM_EXT_OVERLAY_DIR, &st) == 0) {
+    input_dirs.push_back(AssetManager::SYSTEM_EXT_OVERLAY_DIR);
   }
 
   if (stat(AssetManager::ODM_OVERLAY_DIR, &st) == 0) {