Update return value after method exit hook callback

MethodExitHook could potentially cause a GC and we need to update
the return value since GC could move a reference.

Test: art/test.py
Bug: 208587492
Change-Id: Id734a08dd5586c88ac467aa88013f9616cbe4203
diff --git a/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc b/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
index 2086fa2..898b34d 100644
--- a/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
+++ b/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
@@ -2717,6 +2717,7 @@
     if (is_ref) {
       // Restore the return value if it's a reference since it might have moved.
       *reinterpret_cast<mirror::Object**>(gpr_result) = res.Get();
+      return_value.SetL(res.Get());
     }
   }