Add android semantics integration test to device lab (#20971)

dev/devicelab/manifest.yaml

diff --git a/dev/devicelab/manifest.yaml b/dev/devicelab/manifest.yaml
index 2bae9d7..8ffc13f 100644
--- a/dev/devicelab/manifest.yaml
+++ b/dev/devicelab/manifest.yaml
@@ -136,6 +136,13 @@
     stage: devicelab
     required_agent_capabilities: ["mac/android"]
 
+  android_semantics_integration_test:
+    description: >
+      Tests that the Android accessibility bridge produces correct semantics.
+    stage: devicelab
+    required_agent_capabilities: ["mac/android"]
+    flaky: true
+
   run_release_test:
     description: >
       Checks that `flutter run --release` does not crash.