fix name

Author: fsx950223

efficientnetv2/utils.py

@@ -411,7 +411,7 @@ def set_precision_policy(policy_name=None):
   logging.info('use mixed precision policy name %s', policy_name)
   tf.compat.v1.keras.layers.enable_v2_dtype_behavior()
   policy = tf.keras.mixed_precision.Policy(policy_name)
-  tf.keras.mixed_precision.set_policy(policy)
+  tf.keras.mixed_precision.set_global_policy(policy)
 
 
 def build_model_with_precision(pp, mm, ii, tt, *args, **kwargs):