fix(@angular/cli): prefer installed package as fallback when listing package groups

Previously, the package group name defaulted to the first item in the list. This update prioritizes an installed package as the fallback instead.

Closes angular#29627

Author: alan-agius4

packages/angular/cli/src/commands/update/schematic/index.ts

@@ -471,19 +471,24 @@ function _usageMessage(
     )
     .map(({ name, info, version, tag, target }) => {
       // Look for packageGroup.
-      const packageGroup = target['ng-update']?.['packageGroup'];
+      const ngUpdate = target['ng-update'];
+      const packageGroup = ngUpdate?.['packageGroup'];
       if (packageGroup) {
         const packageGroupNames = Array.isArray(packageGroup)
           ? packageGroup
           : Object.keys(packageGroup);
+        const packageGroupName =
+          ngUpdate?.['packageGroupName'] || packageGroupNames.find((n) => infoMap.has(n));
 
-        const packageGroupName = target['ng-update']?.['packageGroupName'] || packageGroupNames[0];
         if (packageGroupName) {
           if (packageGroups.has(name)) {
             return null;
           }
 
-          packageGroupNames.forEach((x: string) => packageGroups.set(x, packageGroupName));
+          for (const groupName of packageGroupNames) {
+            packageGroups.set(groupName, packageGroupName);
+          }
+
           packageGroups.set(packageGroupName, packageGroupName);
           name = packageGroupName;
         }