Fix UnbundledProductApp test to allow extendend public libraries.

This fixes the test to conform with the change in
https://r.android.com/2165025. The test only broke on devices that do
have extended public libraries, in particular wembley.

Test: atest libnativeloader_test
Bug: 242016740
Bug: 237572732
Change-Id: I1400a701a622f9f35b3ce0781575134faca679ae
diff --git a/libnativeloader/native_loader_test.cpp b/libnativeloader/native_loader_test.cpp
index 85cb36d..7bf4cb7 100644
--- a/libnativeloader/native_loader_test.cpp
+++ b/libnativeloader/native_loader_test.cpp
@@ -167,13 +167,16 @@
 
 /////////////////////////////////////////////////////////////////
 
-std::string default_public_and_extended_libraries() {
-  std::string public_libs = default_public_libraries();
+std::string append_extended_libraries(const std::string& libs) {
   const std::string& ext_libs = extended_public_libraries();
   if (!ext_libs.empty()) {
-    public_libs = public_libs + ":" + ext_libs;
+    return libs + ":" + ext_libs;
   }
-  return public_libs;
+  return libs;
+}
+
+std::string default_public_and_extended_libraries() {
+  return append_extended_libraries(default_public_libraries());
 }
 
 class NativeLoaderTest_Create : public NativeLoaderTest {
@@ -380,7 +383,7 @@
     expected_permitted_path =
         expected_permitted_path + ":/product/" LIB_DIR ":/system/product/" LIB_DIR;
     expected_shared_libs_to_platform_ns =
-        default_public_libraries() + ":" + llndk_libraries_product();
+        append_extended_libraries(default_public_libraries() + ":" + llndk_libraries_product());
     expected_link_with_vndk_product_ns = true;
   }
   SetExpectations();