v2 missing setMetricCollector

### Describe the bug

In v1 for Java, one could call AwsSdkMetrics.setMetricCollector(new MyCustomCollector()) if you wanted SDK client metrics but didn't want to use CloudWatch (we use Prometheus and Grafana). With a custom collector, we could automatically transform any AWS service call in the application to a Prometheus metric without having to wrap each and every call site or client reference in the codebase.

### Expected Behavior

Single point to register and transform all AWS SDK metrics to custom output.

### Current Behavior

No such equivalent API appears to exist in v2.

### Reproduction Steps

Nothing in the JavaDocs or blog posts seem to show any alternatives. The bug is that v1 behavior cannot be reproduced.

### Possible Solution

Re-implement a AwsSdkMetrics.setMetricCollector(...) equivalent for v2.

### Additional Information/Context

_No response_

### AWS Java SDK version used

2.17.220

### JDK version used

17.0.1

### Operating System and version

MacOS 12.2.1