test: update rule tests

Author: incendial

test/analyzers/lint_analyzer/rules/rules_list/avoid_unnecessary_setstate/avoid_unnecessary_setstate_test.dart

@@ -54,11 +54,11 @@ void main() {
           'myMethod()',
         ],
         messages: [
-          'Avoid calling unnecessary setState.',
-          'Avoid calling unnecessary setState.',
-          'Avoid calling unnecessary setState.',
-          'Avoid calling unnecessary setState.',
-          'Avoid calling unnecessary setState.',
+          'Avoid calling unnecessary setState. Consider changing the state directly.',
+          'Avoid calling unnecessary setState. Consider changing the state directly.',
+          'Avoid calling unnecessary setState. Consider changing the state directly.',
+          'Avoid calling unnecessary setState. Consider changing the state directly.',
+          'Avoid calling unnecessary setState. Consider changing the state directly.',
           'Avoid calling a method with setState.',
           'Avoid calling a method with setState.',
         ],