### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

PutMetricData with arrays of values does not work properly. Zero values seem to be published. PutMetricData with a single value works as expected. This happens to both CLI and SDK.

### Expected Behavior

PutMetricData with arrays of values should work as publishing a single value.

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    docker run localstack/localstack:1.2.0

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)
```
awslocal cloudwatch put-metric-data --namespace test --metric-data MetricName=TestCounter,Values=10,1,Counts=1,1
awslocal cloudwatch get-metric-statistics --namespace test --metric-name TestCounter --statistics Maximum --period 60 --start-time 2022-11-9T00:00:00Z --end-time 2022-11-11T00:00:00Z
{
    "Label": "TestCounter",
    "Datapoints": [
        {
            "Timestamp": "2022-11-09T23:25:10+00:00",
            "Maximum": 0.0,
            "ExtendedStatistics": {}
        },
        {
            "Timestamp": "2022-11-09T23:27:10+00:00",
            "Maximum": 0.0,
            "ExtendedStatistics": {}
        }
    ]
}
```



### Environment

```markdown
- OS: Mac Monterey
- LocalStack: 1.2.0
```


### Anything else?

_No response_
ok_actions=request.get("OKActions", []),
            insufficient_data_actions=request.get("InsufficientDataActions", []),
            unit=None,
            actions_enabled=request.get("ActionsEnabled"),
            treat_missing_data=None,
            evaluate_low_sample_count_percentile=None,
            threshold_metric_id=None,
            rule=request.get("AlarmRule"),
            tags=request.get("Tags", []),
        )
        LOG.warning(
            "Composite Alarms configuration is not yet supported, alarm state will not be evaluated"
        )
    @handler("EnableAlarmActions")
    def enable_alarm_actions(self, context: RequestContext, alarm_names: AlarmNames) -> None:
        _set_alarm_actions(context, alarm_names, enabled=True)
    @handler("DisableAlarmActions")
    def disable_alarm_actions(self, context: RequestContext, alarm_names: AlarmNames) -> None:
        _set_alarm_actions(context, alarm_names, enabled=False)
    @handler("DescribeAlarms", expand=False)
    def describe_alarms(
        self, context: RequestContext, request: DescribeAlarmsInput
    ) -> DescribeAlarmsOutput:
        response = moto.call_moto(context)
        for c in response["CompositeAlarms"]:
            _cleanup_describe_output(c)
        for m in response["MetricAlarms"]:
            _cleanup_describe_output(m)
        return response