Test the plugin by default in gerrit-plugin-build job

This sets the default bazelisk test target for this job to
"plugins/$plugin_name/..." which should work for most plugins.  If
a particular plugin needs a different test target, we can still
override it for that plugin.

Change-Id: I6af7eca78ad1b191bb32c59c5a57c36916e07c90
diff --git a/zuul.d/jobs.yaml b/zuul.d/jobs.yaml
index 550a83a..46b0886 100644
--- a/zuul.d/jobs.yaml
+++ b/zuul.d/jobs.yaml
@@ -60,7 +60,8 @@
 
       .. zuul:jobvar:: baselisk_test_targets
 
-         The bazelisk targets to test.
+         The bazelisk targets to test.  Defaults to
+         "plugins/{{gerrit_plugin }}/..."
     run: playbooks/gerrit-plugin/build.yaml
     nodeset:
       nodes:
@@ -69,4 +70,5 @@
     vars:
       gerrit_plugin: "{{ zuul.project.short_name }}"
       bazelisk_targets: "plugins/{{ gerrit_plugin }}:{{ gerrit_plugin }}"
+      bazelisk_test_targets: "plugins/{{ gerrit_plugin }}/..."
       zuul_work_dir: "{{ ansible_user_dir }}/src/gerrit.googlesource.com/gerrit"