# 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"
```

stream_arn = data.get('StreamARN')
                cons_name = data.get('ConsumerName')
                cons_arn = data.get('ConsumerARN')
                return (c.get('ConsumerARN') == cons_arn or
                    (c.get('StreamARN') == stream_arn and c.get('ConsumerName') == cons_name))
            STREAM_CONSUMERS = [c for c in STREAM_CONSUMERS if not consumer_matches(c)]
            return {}
        elif action == 'ListStreamConsumers':
            result = {
                'Consumers': [c for c in STREAM_CONSUMERS if c.get('StreamARN') == data.get('StreamARN')]
            }
            return encoded_response(result, encoding_type)