Update ExperimentalDecodeProgram, when postprocess infer "cumulative_num_examples" from "num_samples_in_batch", allows there's sliced metrics, like "num_samples_in_batch/Test" to infer "cumulative_num_examples/Test".
Update ExperimentalDecodeProgram, when postprocess infer "cumulative_num_examples" from "num_samples_in_batch", allows there's sliced metrics, like "num_samples_in_batch/Test" to infer "cumulative_num_examples/Test".

PiperOrigin-RevId: 464944542

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