private static AeadParameters makeRawAesCtrHmacAead(AesCtrHmacAeadParameters parameters)
      throws GeneralSecurityException {
    return AesCtrHmacAeadParameters.builder()
        .setAesKeySizeBytes(parameters.getAesKeySizeBytes())
        .setHmacKeySizeBytes(parameters.getHmacKeySizeBytes())
        .setTagSizeBytes(parameters.getTagSizeBytes())
        .setIvSizeBytes(parameters.getIvSizeBytes())
        .setHashType(parameters.getHashType())
        .setVariant(AesCtrHmacAeadParameters.Variant.NO_PREFIX)
        .build();
  }
Creates a "new" key from a parameters.

<p>While this creates a new Key object, it doesn't actually create a new key. It simply creates
the key object corresponding to this parameters object. Creating a new key would require to
call an API in the KMS, which this method does not do.

<p>The reason this method exists is that in the past, Tink did not provide an API for the user
to create a key object by themselves. Instead, users had to always create a Key from a key
template (which is now a Parameters object) via {@code KeysetHandle.generateNew(template);}. To
support old usages, we need to register this creator.
java_src/src/main/java/com/google/crypto/tink/aead/KmsEnvelopeAeadKeyManager.java