Fix logging configuration for AwsSdkMetrics logger

This commit fixes an issue with the configuration for the AwsSdkMetrics
logger; the issue is that the logging configuration had used underscores
instead of periods for the settings key (the perils of lenient settings
parsing).

Relates #20313

plugins/repository-s3/config/repository-s3/log4j2.properties

@@ -4,5 +4,5 @@ logger.com_amazonaws.level = warn
 logger.com_amazonaws_jmx_SdkMBeanRegistrySupport.name = com.amazonaws.jmx.SdkMBeanRegistrySupport
 logger.com_amazonaws_jmx_SdkMBeanRegistrySupport.level = error
 
-logger_com_amazonaws_metrics_AwsSdkMetrics.name = com.amazonaws.metrics.AwsSdkMetrics
-logger_com_amazonaws_metrics_AwsSdkMetrics.level = error
+logger.com_amazonaws_metrics_AwsSdkMetrics.name = com.amazonaws.metrics.AwsSdkMetrics
+logger.com_amazonaws_metrics_AwsSdkMetrics.level = error