Revise breaking change doc areas (#80761)

PR #79162 revised the breaking changes categories in the doc. Follow this by revising
the categories that changelog YAML files can use.

build-tools-internal/src/main/resources/changelog-schema.json

@@ -191,33 +191,18 @@
     "breakingArea": {
       "type": "string",
       "enum": [
-        "API",
-        "Aggregation",
-        "Allocation",
-        "Authentication",
-        "CCR",
-        "Cluster",
-        "Discovery",
-        "Engine",
-        "HTTP",
-        "Highlighters",
-        "Indices",
-        "Java",
-        "License Information",
+        "Cluster and node setting",
+        "Command line tool",
+        "Index setting",
+        "JVM option",
+        "Java API",
         "Logging",
-        "Machine Learning",
-        "Mappings",
-        "Networking",
+        "Mapping",
         "Packaging",
-        "Plugins",
-        "Script Cache",
-        "Search Changes",
-        "Search",
-        "Security",
-        "Settings",
-        "Snapshot and Restore",
-        "Transform",
-        "Transport"
+        "Painless",
+        "REST API",
+        "System requirement",
+        "Transform"
       ]
     },
     "additionalProperties": false

docs/changelog/78968.yaml

@@ -5,7 +5,7 @@ type: breaking
 issues: []
 breaking:
   title: HTTP Status code has changed for the Cluster Health API in case of a server timeout
-  area: API
+  area: REST API
   details: |-
     The cluster health API includes options for waiting
     for certain health conditions to be satisfied. If the requested conditions are