code: public Blob createEncryptedBlob(String bucketName, String blobName, String encryptionKey) {
      // [START storageUploadEncryptedFile]
      byte[] data = "Hello, World!".getBytes(UTF_8);
  
      BlobId blobId = BlobId.of(bucketName, blobName);
      BlobInfo blobInfo = BlobInfo.newBuilder(blobId).setContentType("text/plain").build();
      Blob blob = storage.create(blobInfo, data, BlobTargetOption.encryptionKey(encryptionKey));
      // [END storageUploadEncryptedFile]
      return blob;
    }
docs: [VARIABLE "my_encryption_key"]