message: Disable new batchnorm codepath if momentum is not a Python float or int.
diff: @@ -545,7 +545,8 @@ class BatchNormalizationBase(Layer):
  # take exponential_avg_factor as a tensor input.
  use_fused_avg_updates = (
  compat.forward_compatible(2020, 3, 6) and
  - ops.executing_eagerly_outside_functions())
  + ops.executing_eagerly_outside_functions() and
  + isinstance(self.momentum, (float, int)))
  if use_fused_avg_updates:
  exponential_avg_factor = 1.0 - self.momentum
  else:
  