Preserve the processRequests and processHandles metrics

The `processResources` metrics depend on the
`process.getActiveResourcesInfo()` API which is still experimental, so
we shouldn't remove the existing metrics in favour of that quite yet.

Signed-off-by: Darshan Sen <raisinten@gmail.com>

CHANGELOG.md

@@ -23,14 +23,16 @@ project adheres to [Semantic Versioning](http://semver.org/).
   causing vscode to think that push/pushAdd and delete didn't promise
   resulting in incorrect behavior.
 
-- The `processHandles` and `processRequests` metrics were replaced by the more
-  advanced `processResources` metric, which keeps a track of all sorts of active
-  resources. It consists of the following gauges:
+### Added
+
+- The `processResources` metric was added, which keeps a track of all sorts of
+  active resources. It consists of the following gauges:
   - `nodejs_active_resources` - Number of active resources that are currently
     keeping the event loop alive, grouped by async resource type.
   - `nodejs_active_resources_total` - Total number of active resources.
-
-### Added
+    It is supposed to provide the combined result of the `processHandles` and
+    `processRequests` metrics along with information about any other types of
+    async resources that these metrics do not keep a track of (like timers).
 
 ## [14.0.0] - 2021-09-18
 

lib/defaultMetrics.js

@@ -26,7 +26,9 @@ const metrics = {
 	eventLoopLag,
 	...(typeof process.getActiveResourcesInfo === 'function'
 		? { processResources }
-		: { processHandles, processRequests }),
+		: {}),
+	processHandles,
+	processRequests,
 	heapSizeAndUsed,
 	heapSpacesSizeAndUsed,
 	version,