Vault - Token mode is not renewed

[Dugong42]

I'm using vault.auth.method=Token to authenticate with Vault, but I've observed that token renewal does not work.

PR #344 introduced token renewal for AppRole, which tries to renew when the initial AuthResult has a TTL > 0.

csid-secrets-providers/vault/src/main/java/io/confluent/csid/config/provider/vault/VaultClientImpl.java

Lines 152 to 158 in a41ab29

	if (result.ttl().isPresent() && result.ttl().get() > 0) {
	log.debug("ctor() - AuthResult does have a ttl - scheduling token renewal.");
	executorService.scheduleAtFixedRate(() -> authenticateVault(config, vaultConfig),
	0, result.ttl().get() - (result.ttl().get() / 10), TimeUnit.SECONDS);
	} else {
	log.debug("ctor() - AuthResult does not have a ttl so not scheduling token refresh.");
	}

The scheduled task triggers authentication, which works for AppRole.
However this implementation currently does not work with the Token method.

For the Token method, authentication only calls auth/token/lookup-self, which does not renew. It should also call auth/token/renew-self.

csid-secrets-providers/vault/src/main/java/io/confluent/csid/config/provider/vault/AuthHandler.java

Lines 183 to 195 in a41ab29

	static class Token extends AuthHandler {
	@Override
	public AuthMethod method() {
	return AuthMethod.Token;
	}
	@Override
	public AuthResult execute(VaultConfigProviderConfig config, Vault vault) throws VaultException {
	LookupResponse lookupResponse = vault.auth().lookupSelf();
	return result(lookupResponse);
	}
	}