message: API changes to allow TPU embedding table sizes that do not fit in 32-bit
  integers. Larger tables do not work correctly yet; this is just changing some
  of the external APIs.
diff: @@ -11,7 +11,7 @@ message TPUEmbeddingConfiguration {
  // Name of the table.
  string name = 1;
  // Size of the vocabulary (i.e., number of rows) in the table.
  - int32 vocabulary_size = 2;
  + int64 vocabulary_size = 2;
  // The embedding dimension (i.e., the width of the embedding table).
  int32 dimension = 3;
  // Number of features mapped to this table.
  