Increase default max retries for key vault requests #589

Currently, the default minimum refresh interval for configuration settings is 30 seconds. We've seen that some customers who use Key Vault secrets and have a shorter refresh interval may run into issues where Key Vault responds various errors, like with a 429 status code, when refreshing the secret. Because refreshing without the updated secret could have unexpected consequences, we can instead set the default maximum retries for the Key Vault client to the maximum value. This ensures that the provider will not skip loading a secret if Key Vault is still able to retry the request but will still handle any exceptions thrown by Key Vault the same as it does now.