message: Add proto_keyset_format.h to the public API in blaze & bazel.
diff: @@ -1120,6 +1120,7 @@ cc_library(
  srcs = ["proto_keyset_format.cc"],
  hdrs = ["proto_keyset_format.h"],
  include_prefix = "tink",
  + visibility = ["//visibility:public"],
  deps = [
  ":binary_keyset_reader",
  ":binary_keyset_writer",
  