Catch tf.text NotFoundError:

tensorflow.python.framework.errors_impl.NotFoundError: /usr/local/lib/python3.6/dist-packages/tensorflow_text/python/metrics/_text_similarity_metric_ops.so: undefined symbol: _ZN10tensorflow6StatusC1ENS_5error4CodeEN4absl12lts_2021032411string_viewEOSt6vectorINS_10StackFrameESaIS7_EE

PiperOrigin-RevId: 368978629

official/nlp/modeling/layers/text_layers.py

@@ -22,6 +22,9 @@ try:
   import tensorflow_text as text  # pylint: disable=g-import-not-at-top
 except ImportError:
   text = None
+except tf.errors.NotFoundError as e:
+  logging.warn("Encountered error when importing tensorflow_text: %s", e)
+  text = None
 
 
 def _check_if_tf_text_installed():