Update micrometer tests following upstream changes

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/export/datadog/DatadogPropertiesTests.java

@@ -32,7 +32,7 @@ public class DatadogPropertiesTests extends StepRegistryPropertiesTests {
 	@Override
 	public void defaultValuesAreConsistent() {
 		DatadogProperties properties = new DatadogProperties();
-		DatadogConfig config = DatadogConfig.DEFAULT;
+		DatadogConfig config = (key) -> null;
 		assertStepRegistryDefaultValues(properties, config);
 		assertThat(properties.isDescriptions()).isEqualTo(config.descriptions());
 		assertThat(properties.getHostTag()).isEqualTo(config.hostTag());

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/export/dynatrace/DynatracePropertiesTests.java

@@ -32,7 +32,7 @@ public class DynatracePropertiesTests extends StepRegistryPropertiesTests {
 	@Override
 	public void defaultValuesAreConsistent() {
 		DynatraceProperties properties = new DynatraceProperties();
-		DynatraceConfig config = DynatraceConfig.DEFAULT;
+		DynatraceConfig config = (key) -> null;
 		assertStepRegistryDefaultValues(properties, config);
 		assertThat(properties.getTechnologyType()).isEqualTo(config.technologyType());
 	}

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/export/newrelic/NewRelicPropertiesTests.java

@@ -32,7 +32,7 @@ public class NewRelicPropertiesTests extends StepRegistryPropertiesTests {
 	@Override
 	public void defaultValuesAreConsistent() {
 		NewRelicProperties properties = new NewRelicProperties();
-		NewRelicConfig config = NewRelicConfig.DEFAULT;
+		NewRelicConfig config = (key) -> null;
 		assertStepRegistryDefaultValues(properties, config);
 		// apiKey and account are mandatory
 		assertThat(properties.getUri()).isEqualTo(config.uri());

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/export/signalfx/SignalFxPropertiesTests.java

@@ -32,7 +32,7 @@ public class SignalFxPropertiesTests extends StepRegistryPropertiesTests {
 	@Override
 	public void defaultValuesAreConsistent() {
 		SignalFxProperties properties = new SignalFxProperties();
-		SignalFxConfig config = SignalFxConfig.DEFAULT;
+		SignalFxConfig config = (key) -> null;
 		assertStepRegistryDefaultValues(properties, config);
 		// access token is mandatory
 		assertThat(properties.getUri()).isEqualTo(config.uri());