### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When calling 

`cloudWatchClient.EnableAlarmActions(&cloudwatch.EnableAlarmActionsInput{AlarmNames: alarmNames})`

with golang I receive a SerializationError with bytes in the error message saying: 

`<!DOCTYPE HTM |UBLIC "-//W3C//DTD HTML 3.2 Final//EN">.<title>500 Internal Server Error</title>.<h1>Internal Server Error</h1>.<p>The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.`

I believe this is a bug, since other cloudwatch operations like "DescribeAlarms" work flawlessly with the same client.

### Expected Behavior

I expected the call to go through without any errors

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

Start localstack, create alarms and call cloudwatch "EnableAlarmActions"

### Environment

_No response_

### Anything else?

_No response_
cloudwatch_client.put_metric_data(
            Namespace="AWS/EC2",
            MetricData=[
                {
                    "MetricName": "CPUUtilization",
                    "Dimensions": [{"Name": "InstanceId", "Value": "i-46cdcd06a11207ab3"}],
                    "Value": 15,
                }
            ],
        )
        
        results = cloudwatch_client.list_metrics(Namespace="AWS/EC2")["Metrics"]
        assert 2 == len(results)
    def test_put_metric_alarm_escape_character(self, cloudwatch_client):
        cloudwatch_client.put_metric_alarm(
            AlarmName="cpu-mon",
            AlarmDescription="<",
            MetricName="CPUUtilization-2",
            Namespace="AWS/EC2",
            Statistic="Sum",
            Period=600,
            Threshold=1,
            ComparisonOperator="GreaterThanThreshold",
            EvaluationPeriods=1,
            AlarmActions=["arn:aws:sns:us-east-1:111122223333:MyTopic"],
        )
        result = cloudwatch_client.describe_alarms()
        assert result.get("MetricAlarms")[0]["AlarmDescription"] == "<"
        cloudwatch_client.delete_alarms(AlarmNames=["cpu-mon"])
    def test_set_alarm(