Send data for all devices in each variant

Instead of only the first.
As per discussed in paaHJt-3od-p2#comment-6090

Author: AliSoftware

lib/fastlane/plugin/wpmreleasetoolkit/actions/ios/ios_send_app_size_metrics.rb

@@ -16,11 +16,12 @@ def self.run(params)
         if File.exist?(app_thinning_plist_path)
           plist = Plist.parse_xml(app_thinning_plist_path)
           plist['variants'].each do |_key, variant|
-            # FIXME: We should probably not take only the first `variantDescriptor` from the list. But that'll do for now as a draft implementation.
-            vd = variant['variantDescriptors']&.first
-            variant_metadata = vd.nil? ? { device: 'Universal' } : { device: vd['device'], 'OS Version': vd['os-version'] }
-            payload.add_metric(name: 'Download Size', value: variant['sizeCompressedApp'], meta: variant_metadata)
-            payload.add_metric(name: 'Install Size', value: variant['sizeUncompressedApp'], meta: variant_metadata)
+            variant_descriptors = variant['variantDescriptors'] || [{ 'device' => 'Universal' }]
+            variant_descriptors.each do |desc|
+              variant_metadata = { device: desc['device'], 'OS Version': desc['os-version'] }
+              payload.add_metric(name: 'Download Size', value: variant['sizeCompressedApp'], meta: variant_metadata)
+              payload.add_metric(name: 'Install Size', value: variant['sizeUncompressedApp'], meta: variant_metadata)
+            end
           end
         end