Revert "Marks Linux firebase_oriol33_abstract_method_smoke_test to be unflaky" (#130497)

Reverts flutter/flutter#128398

See e.g.
https://ci.chromium.org/ui/p/flutter/builders/try/Linux%20firebase_oriol33_abstract_method_smoke_test/350/overview

.ci.yaml

@@ -412,6 +412,7 @@ targets:
       - .ci.yaml
 
   - name: Linux firebase_oriol33_abstract_method_smoke_test
+    bringup: true
     recipe: firebaselab/firebaselab
     timeout: 60
     properties: