Mark test as non-flaky now that it's been fixed (#16033)

diff --git a/dev/devicelab/manifest.yaml b/dev/devicelab/manifest.yaml
index 6e2de5f..4fb4ebb 100644
--- a/dev/devicelab/manifest.yaml
+++ b/dev/devicelab/manifest.yaml
@@ -249,7 +249,6 @@
       test can run on off-the-shelf infrastructures, such as Firebase Test Lab.
     stage: devicelab
     required_agent_capabilities: ["linux/android"]
-    flaky: true
 
   # iOS on-device tests