Add platform_interaction_test_swift to devicelab (#35775)

dev/devicelab/manifest.yaml

diff --git a/dev/devicelab/manifest.yaml b/dev/devicelab/manifest.yaml
index 579508a..5cafc98 100644
--- a/dev/devicelab/manifest.yaml
+++ b/dev/devicelab/manifest.yaml
@@ -414,10 +414,17 @@
 
   platform_channel_sample_test_ios:
     description: >
-      Runs a driver test on the Platform Channel sample app on iPhone 6.
+      Runs a driver test on the Platform Channel sample app on iPhone 6 Objective-C project.
     stage: devicelab_ios
     required_agent_capabilities: ["mac/ios"]
 
+  platform_channel_sample_test_swift:
+    description: >
+      Runs a driver test on the Platform Channel sample app on iPhone 6 Swift project.
+    stage: devicelab_ios
+    required_agent_capabilities: ["mac/ios"]
+    flaky: true
+
   platform_view_ios__start_up:
     description: >
       Verifies that Platform View can be used from an iOS project.