我对AWSsessiontoken和AWSCognitoID之间的区别有点困惑，它们是一样的吗？因为通过这段代码AWSCognitoCredentialsProvider*credentialsProvider=[[AWSCognitoCredentialsProvideralloc]initWithRegionType:AWSRegionUSEast1identityPoolId:@"my-identity-pool"];AWSServiceConfiguration*configuration=[[AWSServiceConfigurationalloc]initWithRegio