Add property to disable Spring Security observations

Setting 'management.observations.spring-security.enabled' installs an
ObservationPredicate, which prevents all observations starting with
'spring.security.' to be created.

Closes gh-34802

spring-boot-project/spring-boot-docs/src/docs/asciidoc/actuator/observability.adoc

@@ -37,4 +37,16 @@ Commons key-values are applied to all observations as low cardinality key-values
 
 The preceding example adds `region` and `stack` key-values to all observations with a value of `us-east-1` and `prod`, respectively.
 
+[[actuator.observability.preventing-observations]]
+=== Preventing Observations
+
+If you'd like to prevent some observations from being reported, you can register beans of type `ObservationPredicate`.
+Observations are only reported if all the `ObservationPredicate` beans return `true` for that observation.
+
+include::code:MyObservationPredicate[]
+
+The preceding example will prevent all observations with a name starting with "denied.prefix.".
+
+TIP: If you want to prevent Spring Security from reporting observations, set the property configprop:management.observations.spring-security.enabled[] to `false`.
+
 The next sections will provide more details about logging, metrics and traces.

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/actuator/observability/preventingobservations/MyObservationPredicate.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.observability.preventingobservations;
+
+import io.micrometer.observation.Observation.Context;
+import io.micrometer.observation.ObservationPredicate;
+
+import org.springframework.stereotype.Component;
+
+@Component
+class MyObservationPredicate implements ObservationPredicate {
+
+	@Override
+	public boolean test(String name, Context context) {
+		return !name.startsWith("denied.prefix.");
+	}
+
+}