Supports SSH algorithms other than RSA

[yunchen-myob]

Is your feature request related to a problem? Please describe.
SSH has several different types of algorithms for generating the key pair, you can reference this blog: https://goteleport.com/blog/comparing-ssh-keys/
But for now, this SDK can only support the RSA. The method in SDK to read the private key like below:

public static X509KeyManager keyManager(byte[] privateKeyPem, byte[] certificatePem)
      throws SSLException {
     
      ......
      KeyFactory factory = KeyFactory.getInstance("RSA");
      PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(decodePem(privateKeyPem));
      PrivateKey key = factory.generatePrivate(keySpec);
      ......
  }

As you can see in the above code, the SDK only instance the key using RSA algorithms.
I have also seen another similar issue here: #4751

Describe the solution you'd like
It can have 2 solutions here in my mind:

1. Support another parameter for the OtlpGrpcSpanExporterBuilder.setClientTls method named like algorithm.
2. Get the algorithm from the certificatePem and used to read the private key.

Describe alternatives you've considered
I purpose the soluton2. Automated reading will save developers a lot of time as they no longer need to know the algorithmic details of the certificate.

Additional context
Nothing here.