Mark non-flaky test as such (#33269)

dev/devicelab/manifest.yaml

diff --git a/dev/devicelab/manifest.yaml b/dev/devicelab/manifest.yaml
index 015125f..db284d2 100644
--- a/dev/devicelab/manifest.yaml
+++ b/dev/devicelab/manifest.yaml
@@ -153,7 +153,6 @@
       Check that driver will print warnings when traceAction is called in debug mode.
     stage: devicelab
     required_agent_capabilities: ["mac/android"]
-    flaky: true
 
   cull_opacity_perf__timeline_summary:
     description: >