[face_detector][test] Fix warning in .launch format.

[face_detector][test] Fix namespace in testcases.
[face_detector][test] Increase retry. .bag-based perceptional tests are hard to deterministic, so it makes sense to do this.

face_detector/test/common_rtest.xml

@@ -1,19 +1,28 @@
 <launch>
   <arg name="expected_success" default="true" />
+  <arg name="hz" default="30.0" />
+  <arg name="hz_error" default="29.9" />
+  <arg name="RETRY_TEST" default="5" />
   <arg name="testnode_name" default="hztest1" />
 
-  <test test-name="hztest_test" pkg="rostest" type="hztest" name="$(arg testnode_name)">
-    <group unless="$(arg expected_success)">
-      <node pkg="rosbag" type="play" name="play" args="-r 0.5 $(find face_detector)/test/face_detector_noface_test_diamondback.bag"/>
+  <group unless="$(arg expected_success)">
+    <node pkg="rosbag" type="play" name="play" args="-r 0.5 $(find face_detector)/test/face_detector_noface_test_diamondback.bag"/>
+
+    <test test-name="hztest_test" pkg="rostest" type="hztest" name="$(arg testnode_name)" retry="$(arg RETRY_TEST)">
+      <param name="topic" value="face_detector/people_tracker_measurements_array" />
       <param name="hz" value="0.0" />
-    </group>
-    <group if="$(arg expected_success)">
-      <node pkg="rosbag" type="play" name="play" args="-r 0.5 $(find face_detector)/test/face_detector_withface_test_diamondback.bag"/>
-      <param name="hz" value="30.0" />
-      <param name="hzerror" value="29.9" />
-    </group>
-
-    <param name="topic" value="face_detector/people_tracker_measurements_array" />
-    <param name="test_duration" value="15.0" />
-  </test>
+      <param name="hzerror" value="0.0" />    
+      <param name="test_duration" value="15.0" />
+    </test>
+  </group>
+  <group if="$(arg expected_success)">
+    <node pkg="rosbag" type="play" name="play" args="-r 0.5 $(find face_detector)/test/face_detector_withface_test_diamondback.bag"/>
+
+    <test test-name="hztest_test" pkg="rostest" type="hztest" name="$(arg testnode_name)" retry="$(arg RETRY_TEST)">
+      <param name="topic" value="face_detector/people_tracker_measurements_array" />
+      <param name="hz" value="$(arg hz)" />
+      <param name="hzerror" value="$(arg hz_error)" />    
+      <param name="test_duration" value="15.0" />
+    </test>
+  </group>
 </launch>