Make Transaction inherit Parcelable at public level

Bug: 139439952
Test: build, boot, SurfaceFlinger_test
Change-Id: Ib0796def398cbeb295d6cd95b8422ab66bb0b2c5
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index f303a03..64ee65f 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -290,7 +290,7 @@
         std::unordered_set<sp<SurfaceControl>, SCHash> surfaceControls;
     };
 
-    class Transaction : Parcelable {
+    class Transaction : public Parcelable {
         std::unordered_map<sp<IBinder>, ComposerState, IBinderHash> mComposerStates;
         SortedVector<DisplayState > mDisplayStates;
         std::unordered_map<sp<ITransactionCompletedListener>, CallbackInfo, TCLHash>