Context copying is disabling default dimensions

[markkuhn]

Issue

When flushPreserveDimensions is true, the context will disable default dimensions after the first flush.

Reproduction

MetricsLogger logger = new MetricsLogger(environment);
logger.putMetric("Example", 100);
logger.flush();
logger.putMetric("Example", 200);
logger.flush(); // This logger will not contain any default dimensions

Cause

Context copy uses setDimensions() to copy custom dimensions which disables default dimensions.

aws-embedded-metrics-java/src/main/java/software/amazon/cloudwatchlogs/emf/model/MetricDirective.java

Line 171 in ac3e84c

metricDirective.setDimensions(this.dimensions);