Support test trend graph in Build Flow Test Aggregator

Support for configurable test trend graph was added at version 1.2 of
https://wiki.jenkins-ci.org/display/JENKINS/Build+Flow+Test+Aggregator+Plugin.

Change-Id: I5d01fe839cfa4f685f36c3ca0d2418691c4b7ec9

jenkins_jobs/modules/publishers.py

@@ -1959,16 +1959,20 @@ def aggregate_flow_tests(parser, xml_parent, data):
     Requires the Jenkins :jenkins-wiki:`Build Flow Test Aggregator Plugin
     <Build+Flow+Test+Aggregator+Plugin>`.
 
+    :arg bool show-test-results-trend: whether to show test results
+        trend graph (default true)
+
     Example:
 
-    .. literalinclude:: \
-    /../../tests/publishers/fixtures/aggregate-flow-tests.yaml
+    .. literalinclude::
+        /../../tests/publishers/fixtures/aggregate-flow-tests002.yaml
        :language: yaml
 
     """
-    XML.SubElement(xml_parent,
-                   'org.zeroturnaround.jenkins.'
-                   'flowbuildtestaggregator.FlowTestAggregator')
+    agg_flow = XML.SubElement(xml_parent, 'org.zeroturnaround.jenkins.'
+                              'flowbuildtestaggregator.FlowTestAggregator')
+    XML.SubElement(agg_flow, 'showTestResultTrend').text = str(
+        data.get('show-test-results-trend', True)).lower()
 
 
 def cppcheck(parser, xml_parent, data):

tests/publishers/fixtures/aggregate-flow-tests001.xml

@@ -1,6 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <project>
   <publishers>
-    <org.zeroturnaround.jenkins.flowbuildtestaggregator.FlowTestAggregator/>
+    <org.zeroturnaround.jenkins.flowbuildtestaggregator.FlowTestAggregator>
+      <showTestResultTrend>true</showTestResultTrend>
+    </org.zeroturnaround.jenkins.flowbuildtestaggregator.FlowTestAggregator>
   </publishers>
 </project>

tests/publishers/fixtures/aggregate-flow-tests002.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<project>
+  <publishers>
+    <org.zeroturnaround.jenkins.flowbuildtestaggregator.FlowTestAggregator>
+      <showTestResultTrend>false</showTestResultTrend>
+    </org.zeroturnaround.jenkins.flowbuildtestaggregator.FlowTestAggregator>
+  </publishers>
+</project>

tests/publishers/fixtures/aggregate-flow-tests002.yaml

@@ -0,0 +1,3 @@
+publishers:
+  - aggregate-flow-tests:
+      show-test-results-trend: false