AWS Shield DDoSDetected metric splitting to snakecase on change from upper to lowercase letter

[AronNaylor]

When splitting the AWS Shield Advanced DDoSDetected CloudWatch metric, it is incorrectly being parsed as follows due to the linked method:

region: us-east-1
metrics:
- aws_dimensions:
  aws_metric_name: DDoSDetected
  aws_namespace: AWS/DDoSProtection
  aws_statistics:
  - Sum

Becomes:

aws_ddosprotection_ddo_sdetected_sum

This occurs only when a lowercase letter appears in the middle of a word within a metric name which contains multiple words (see example above), but not the namespace (see code refs below).

cloudwatch_exporter/src/main/java/io/prometheus/cloudwatch/CloudWatchCollector.java

Line 427 in 68a84c7

return str.replaceAll("([a-z0-9])([A-Z])", "$1_$2").toLowerCase();

cloudwatch_exporter/src/main/java/io/prometheus/cloudwatch/CloudWatchCollector.java

Line 482 in 68a84c7

safeName(rule.awsNamespace.toLowerCase() + "_" + toSnakeCase(rule.awsMetricName));