Add @Primary to default InMemoryMetricRepository if there is one

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/MetricRepositoryAutoConfiguration.java

@@ -47,6 +47,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.scheduling.annotation.Scheduled;
@@ -158,6 +159,7 @@ public class MetricRepositoryAutoConfiguration {
 	static class LegacyMetricRepositoryConfiguration {
 
 		@Bean
+		@Primary
 		public InMemoryMetricRepository actuatorMetricRepository() {
 			return new InMemoryMetricRepository();
 		}