[SPARK-27997][K8S] Support user-provided OAuth Token Providers

[dongjoon-hyun]

What changes were proposed in this pull request?

This PR aims to support user-provided OAuthTokenProvider implementations to refresh tokens throughout the life of the spark app.

spark.kubernetes.authenticate.submission.oauthTokenProvider=<token>
spark.kubernetes.authenticate.driver.oauthTokenProvider=<token>
spark.kubernetes.authenticate.oauthTokenProvider=<token>

OAuthTokenProvider interface has been stable for two years.

public interface OAuthTokenProvider {
  /**
   * Returns a Bearer token used for authorization between a client
   * and a kubernetes cluster. The token will be injected into an Authorization header.
   *
   * @return oauth token
   */
  String getToken();
}

Why are the changes needed?

• KEP-1205 Bound Service Account Tokens : BoundServiceAccountTokenVolume

Alpha	Beta	GA
1.13	1.21	1.22

• EKS Service Account with 90 Days Expiration

  For Amazon EKS clusters, the extended expiry period is 90 days. Your Amazon EKS cluster's Kubernetes API server rejects requests with tokens that are greater than 90 days old.

Does this PR introduce any user-facing change?

No, this is a framework to support new features. In the future, we may need proper built-in provider implementations for public cloud environments like EKS/GKE/AKS.

How was this patch tested?

N/A