Refactor SecurityMetricType from enum to record for extensibility (#144119)

This PR converts `SecurityMetricType` from an enum to a record, allowing
metric types to be defined outside of security plugin.

It also removes the serverless-only `CLOUD_AUTHC_API_KEY` type, which
will be defined in serverless repo.

Author: slobodanadamovic

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/metric/SecurityMetricType.java

@@ -8,37 +8,24 @@
 package org.elasticsearch.xpack.security.metric;
 
 /**
- * Defines all security metric types that can be collected.
+ * Defines a security metric type that can be collected.
+ * Each metric type has a group, and metric info for tracking success, failure and total time.
  */
-public enum SecurityMetricType {
+public record SecurityMetricType(
+    SecurityMetricGroup group,
+    SecurityMetricInfo successMetricInfo,
+    SecurityMetricInfo failuresMetricInfo,
+    SecurityMetricInfo timeMetricInfo
+) {
 
-    AUTHC_API_KEY(
+    public static final SecurityMetricType AUTHC_API_KEY = new SecurityMetricType(
         SecurityMetricGroup.AUTHC,
         new SecurityMetricInfo("es.security.authc.api_key.success.total", "Number of successful API key authentications.", "count"),
         new SecurityMetricInfo("es.security.authc.api_key.failures.total", "Number of failed API key authentications.", "count"),
         new SecurityMetricInfo("es.security.authc.api_key.time", "Time it took (in nanoseconds) to execute API key authentication.", "ns")
-    ),
+    );
 
-    CLOUD_AUTHC_API_KEY(
-        SecurityMetricGroup.AUTHC,
-        new SecurityMetricInfo(
-            "es.security.authc.cloud_api_key.success.total",
-            "Number of successful cloud API key authentications.",
-            "count"
-        ),
-        new SecurityMetricInfo(
-            "es.security.authc.cloud_api_key.failures.total",
-            "Number of failed cloud API key authentications.",
-            "count"
-        ),
-        new SecurityMetricInfo(
-            "es.security.authc.cloud_api_key.time",
-            "Time it took (in nanoseconds) to execute cloud API key authentication.",
-            "ns"
-        )
-    ),
-
-    AUTHC_SERVICE_ACCOUNT(
+    public static final SecurityMetricType AUTHC_SERVICE_ACCOUNT = new SecurityMetricType(
         SecurityMetricGroup.AUTHC,
         new SecurityMetricInfo(
             "es.security.authc.service_account.success.total",
@@ -55,9 +42,9 @@ public enum SecurityMetricType {
             "Time it took (in nanoseconds) to execute service account authentication.",
             "ns"
         )
-    ),
+    );
 
-    AUTHC_OAUTH2_TOKEN(
+    public static final SecurityMetricType AUTHC_OAUTH2_TOKEN = new SecurityMetricType(
         SecurityMetricGroup.AUTHC,
         new SecurityMetricInfo("es.security.authc.token.success.total", "Number of successful OAuth2 token authentications.", "count"),
         new SecurityMetricInfo("es.security.authc.token.failures.total", "Number of failed OAuth2 token authentications.", "count"),
@@ -66,48 +53,12 @@ public enum SecurityMetricType {
             "Time it took (in nanoseconds) to execute OAuth2 token authentication.",
             "ns"
         )
-    ),
+    );
 
-    AUTHC_REALMS(
+    public static final SecurityMetricType AUTHC_REALMS = new SecurityMetricType(
         SecurityMetricGroup.AUTHC,
         new SecurityMetricInfo("es.security.authc.realms.success.total", "Number of successful realm authentications.", "count"),
         new SecurityMetricInfo("es.security.authc.realms.failures.total", "Number of failed realm authentications.", "count"),
         new SecurityMetricInfo("es.security.authc.realms.time", "Time it took (in nanoseconds) to execute realm authentication.", "ns")
-    ),
-
-    ;
-
-    private final SecurityMetricGroup group;
-    private final SecurityMetricInfo successMetricInfo;
-    private final SecurityMetricInfo failuresMetricInfo;
-    private final SecurityMetricInfo timeMetricInfo;
-
-    SecurityMetricType(
-        SecurityMetricGroup group,
-        SecurityMetricInfo successMetricInfo,
-        SecurityMetricInfo failuresMetricInfo,
-        SecurityMetricInfo timeMetricInfo
-    ) {
-        this.group = group;
-        this.successMetricInfo = successMetricInfo;
-        this.failuresMetricInfo = failuresMetricInfo;
-        this.timeMetricInfo = timeMetricInfo;
-    }
-
-    public SecurityMetricGroup group() {
-        return this.group;
-    }
-
-    public SecurityMetricInfo successMetricInfo() {
-        return successMetricInfo;
-    }
-
-    public SecurityMetricInfo failuresMetricInfo() {
-        return failuresMetricInfo;
-    }
-
-    public SecurityMetricInfo timeMetricInfo() {
-        return timeMetricInfo;
-    }
-
+    );
 }