[fenix] No issue: Restore num-flaky-test-attempts in flank-x86.yml (https://github.com/mozilla-mobile/fenix/pull/9675)

automation/taskcluster/androidTest/flank-x86.yml

@@ -21,6 +21,10 @@ gcloud:
   # see: https://github.com/TestArmada/flank/issues/341
   #results-history-name: tmp_parallel 
 
+  # The number of times a test execution should be re-attempted if one or more failures occur.
+  # The maximum number of reruns allowed is 10. Default is 0, which implies no reruns.
+  num-flaky-test-attempts: 1
+
   # test and app are the only required args
   app: /app/path 
   test: /test/path