message: Fix graph mode test decorator to only check eager
  Checking for tf2 broadly was never the intent of this decorators. As a
  result it did not compose well with run_all_in_graph_and_eager_modes,
  since that only enabled eager execution.
diff: @@ -1212,7 +1212,7 @@ def deprecated_graph_mode_only(func=None):
  return f
  def decorated(self, *args, **kwargs):
  - if tf2.enabled():
  + if context.executing_eagerly():
  with context.graph_mode():
  return f(self, *args, **kwargs)
  else:
  