Use a more stable sorting for the region metadata (#2014)

Sorting region groups based on the numer of regions in the group
generates some unnecessary changes during SDK updates when adding a new
region in a group.

Author: stof

CHANGELOG.md

@@ -16,6 +16,7 @@
 
 - AWS enhancement: Documentation updates.
 - Apply new CodingStandard from latest php-cs-fixer.
+- Use a more stable sorting for the list of generated region metadata
 
 ## 1.10.0
 

src/KmsClient.php

@@ -1326,6 +1326,13 @@ protected function getEndpointMetadata(?string $region): array
                     'signService' => 'kms',
                     'signVersions' => ['v4'],
                 ];
+            case 'eu-isoe-west-1':
+                return [
+                    'endpoint' => 'https://kms.eu-isoe-west-1.cloud.adc-e.uk',
+                    'signRegion' => 'eu-isoe-west-1',
+                    'signService' => 'kms',
+                    'signVersions' => ['v4'],
+                ];
             case 'us-iso-east-1':
             case 'us-iso-west-1':
                 return [
@@ -1350,13 +1357,6 @@ protected function getEndpointMetadata(?string $region): array
                     'signService' => 'kms',
                     'signVersions' => ['v4'],
                 ];
-            case 'eu-isoe-west-1':
-                return [
-                    'endpoint' => 'https://kms.eu-isoe-west-1.cloud.adc-e.uk',
-                    'signRegion' => 'eu-isoe-west-1',
-                    'signService' => 'kms',
-                    'signVersions' => ['v4'],
-                ];
             case 'eu-isoe-west-1-fips':
                 return [
                     'endpoint' => 'https://kms-fips.eu-isoe-west-1.cloud.adc-e.uk',