test(userspace/engine): update integration tests to support enabled-only rules

Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>

test/falco_tests.yaml

@@ -354,7 +354,7 @@ trace_files: !mux
     exit_status: 1
     stdout_is: |+
       1 errors:
-      Rule must have exceptions or condition property
+      Appended rule must have exceptions or condition property
       ---
       - rule: no condition rule
         append: true

test/rules/invalid_append_rule_without_condition.yaml

@@ -1,2 +1,24 @@
+#
+# Copyright (C) 2021 The Falco Authors.
+#
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+- rule: no condition rule
+  desc: simpe rule 
+  condition: evt.type=open
+  output: simple output
+  priority: WARNING
+
 - rule: no condition rule
   append: true