Hold data pointer reference to AAPT2 test file

To try and solve test flakiness, hold the unique_ptr in the method scope to make sure it's cleaned up after we assert on it.

Bug: 123079798

Test: gonna merge and check for failures, since it passes locally

Change-Id: Id348d1112832cbb82f605a84ef675c25a7488b11
diff --git a/tools/aapt2/test/Fixture.h b/tools/aapt2/test/Fixture.h
index 89d3b7b..3079c75 100644
--- a/tools/aapt2/test/Fixture.h
+++ b/tools/aapt2/test/Fixture.h
@@ -83,8 +83,12 @@
   // Creates a minimal android manifest within the test directory and returns the file path.
   std::string GetDefaultManifest();
 
+  // Returns pointer to data inside APK files
+  std::unique_ptr<io::IData> OpenFileAsData(LoadedApk* apk,
+                                            const android::StringPiece& path);
+
   // Asserts that loading the tree from the specified file in the apk succeeds.
-  void AssertLoadXml(LoadedApk* apk, const android::StringPiece& xml_path,
+  void AssertLoadXml(LoadedApk* apk, const io::IData* data,
                      android::ResXMLTree* out_tree);
 
  private: