Add ofs (Ozone Filesystem) support for acquireDelegationToken

public void acquireDelegationToken(final FileSystem fs) throws IOException {
  String tokenKind;
  String scheme = fs.getUri().getScheme();
  if (SWEBHDFS_SCHEME.equalsIgnoreCase(scheme)) {
    tokenKind = SWEBHDFS_TOKEN_KIND.toString();
  } else if (WEBHDFS_SCHEME.equalsIgnoreCase(scheme)) {
    tokenKind = WEBHDFS_TOKEN_KIND.toString();
  } else if (HDFS_URI_SCHEME.equalsIgnoreCase(scheme)) {
    tokenKind = HDFS_DELEGATION_KIND.toString();
  } else {
    LOG.warn("Unknown FS URI scheme: " + scheme);
    // Preserve default behavior
    tokenKind = HDFS_DELEGATION_KIND.toString();
  }

  acquireDelegationToken(tokenKind, fs);
}