Mark non-flaky test as such (#58112)

diff --git a/dev/devicelab/manifest.yaml b/dev/devicelab/manifest.yaml
index 07306b7..521f675 100644
--- a/dev/devicelab/manifest.yaml
+++ b/dev/devicelab/manifest.yaml
@@ -290,7 +290,6 @@
       Measures memory usage of the scroll performance test using DevTools.
     stage: devicelab
     required_agent_capabilities: ["linux/android"]
-    flaky: true
 
   hello_world_android__compile:
     description: >