# Type of request: This is a ...

[x] bug report
[ ] feature request

# Detailed description

Calls to `DescribeStreamConsumer` for the Kinesis service do not return the registered consumer. Calls to `ListStreamConsumers` does correctly show registered consumers.

Filing this issue to document this bug. It looks like `kinesis_listener.py` has mixed naming of `StreamARN` and `StreamArn`, I'll create a PR to fix this evening.

## Expected behavior

Returns registered consumer when queried by stream ARN + consumer name, and stream ARN+ consumer ARN.

## Actual behavior

The returned error is HTTP 400, "Consumer <consumer_name/arn> not found."

# Steps to reproduce

## Command used to start LocalStack

```
SERVICES=kinesis docker-compose up
```
## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)

```
# Setup a stream and register a consumer
awslocal kinesis create-stream --stream-name "test-stream" --shard-count 1
STREAM_ARN=$(awslocal kinesis describe-stream \
    --stream-name "test-stream" \
    --query StreamDescription.StreamARN \
    --output text)
awslocal kinesis register-stream-consumer \
    --stream-arn "$STREAM_ARN" \
    --consumer-name "test-consumer"

# Call by consumer name fails:
awslocal kinesis describe-stream-consumer \
  --stream-arn "$STREAM_ARN" \
  --consumer-name "test-consumer"

# Call by consumer ARN also fails:
awslocal kinesis describe-stream-consumer \
  --stream-arn "$STREAM_ARN" \
  --consumer-arn "$STREAM_ARN/consumer/test-consumer"
```

elif action == 'DescribeStreamConsumer':
            consumer_arn = data.get('ConsumerARN', '')
            consumer_name = data.get('ConsumerName', '')
            stream_arn = data.get('StreamArn', '')
            consumer_to_locate = find_consumer(consumer_arn, consumer_name, stream_arn)
            if(not consumer_to_locate):
                error_msg = 'Consumer %s not found.' % (consumer_arn or consumer_name)
                return simple_error_response(error_msg, 400, 'ResourceNotFoundException', encoding_type)
            creation_timestamp = consumer_to_locate.get('ConsumerCreationTimestamp')
            time_formated = int(creation_timestamp) if encoding_type is not APPLICATION_JSON else creation_timestamp
            result = {
                'ConsumerDescription': {
                    'ConsumerARN': consumer_to_locate.get('ConsumerArn'),
                    'ConsumerCreationTimestamp': time_formated,
                    'ConsumerName': consumer_to_locate.get('ConsumerName'),
                    'ConsumerStatus': 'ACTIVE',
                    'StreamARN': data.get('StreamARN')
                }
            }
            return encoded_response(result, encoding_type)
        elif action == 'SubscribeToShard':
            result = subscribe_to_shard(data, headers)
            return result
        if random.random() < config.KINESIS_ERROR_PROBABILITY:
            if action in ['PutRecord', 'PutRecords']:
                return kinesis_error_response(data, action)
        return True
    def return_response(self, method, path, data, headers, response):
        action = headers.get('X-Amz-Target', '').split('.')[-1]
        data, encoding_type = self.decode_content(data or '{}', True)