Add TPUDistributedVariable as allowed variable type in ema check. Needed when --use_tpu_mirrored_vars turned on.
Add TPUDistributedVariable as allowed variable type in ema check.
Needed when --use_tpu_mirrored_vars turned on.

PiperOrigin-RevId: 443180291

tensorflow/lingvo,tensorflow/lingvo,tensorflow/lingvo,tensorflow/lingvo