Add testcase to test mutually exclusive values

tests/integration/targets/cloudwatch_metric_alarm/tasks/main.yml

@@ -465,6 +465,43 @@
       that:
         - 'alarm_info_no_unit.metric_alarms | length == 0'
 
+  - name: create ec2 metric alarm by providing mutually exclusive values
+    ec2_metric_alarm:
+      dimensions:
+        InstanceId: '{{ ec2_instance_results.instances[0].instance_id }}'
+      state: present
+      name: '{{ alarm_full_name }}'
+      metric: CPUUtilization
+      namespace: AWS/EC2
+      treat_missing_data: missing
+      statistic: Average
+      comparison: LessThanOrEqualToThreshold
+      threshold: 5.0
+      period: 300
+      evaluation_periods: 3
+      description: This will alarm when an instance's cpu usage average is lower than
+        5% for 15 minutes
+      metrics:
+        - id: cpu
+          metric_stat:
+              metric:
+                  dimensions:
+                    - name: "InstanceId"
+                      value: "{{ ec2_instance_results.instances[0].instance_id }}"
+                  metric_name: "CPUUtilization"
+                  namespace: "AWS/EC2"
+              period: 300
+              stat: "Average"
+              unit: "Percent"
+          return_data: true
+    register: ec2_instance_metric_mutually_exclusive
+    ignore_errors: true
+
+  - assert:
+      that:
+      - ec2_instance_metric_mutually_exclusive.failed
+      - '"parameters are mutually exclusive" in ec2_instance_metric_mutually_exclusive.msg'
+
   always:
   - name: try to delete the alarm
     ec2_metric_alarm: