Add 'current-release' and 'previous-release' variables to JJB

Change-Id: If6cb2bfa6a7102413188ba81d87a7575f741271d
Related-Prod: PROD-34955
diff --git a/jobs/templates/released-heat-cicd-pike-dvr-sl.yml b/jobs/templates/released-heat-cicd-pike-dvr-sl.yml
index 79fec53..9c5f6aa 100644
--- a/jobs/templates/released-heat-cicd-pike-dvr-sl.yml
+++ b/jobs/templates/released-heat-cicd-pike-dvr-sl.yml
@@ -33,7 +33,7 @@
         name: PLATFORM_STACK_INSTALL_TIMEOUT
         trim: 'false'
     - string:
-        default: 2019.2.9
+        default: "{previous-version}"
         description: ''
         name: MCP_VERSION
         trim: 'false'
@@ -70,23 +70,23 @@
         name: TCP_QA_REFS
         trim: 'false'
     - string:
-        default: refs/tags/2019.2.9
+        default: refs/tags/{previous-version}
         description: reference to patchset in pipeline-library
         name: PIPELINE_LIBRARY_REF
         trim: 'false'
     - string:
-        default: refs/tags/2019.2.9
+        default: refs/tags/{previous-version}
         description: reference to patchset in mk-pipelines
         name: MK_PIPELINES_REF
         trim: 'false'
     - string:
-        default: refs/tags/2019.2.9
+        default: refs/tags/{previous-version}
         description: Can be 'master' or 'proposed'. If empty, then takes ${{MCP_VERSION}}
           value
         name: COOKIECUTTER_TEMPLATE_COMMIT
         trim: 'false'
     - string:
-        default: refs/tags/2019.2.9
+        default: refs/tags/{previous-version}
         description: Can be 'master' or 'proposed'. If empty, then takes ${{MCP_VERSION}}
           value
         name: SALT_MODELS_SYSTEM_COMMIT
@@ -188,7 +188,7 @@
         name: LAB_PARAM_DEFAULTS
         trim: 'false'
     - string:
-        default: refs/tags/2019.2.9
+        default: refs/tags/{previous-version}
         description: ''
         name: JENKINS_PIPELINE_BRANCH
         trim: 'false'
@@ -198,12 +198,12 @@
         name: TEMPEST_PATTERN
         trim: 'false'
     - string:
-        default: refs/tags/2019.2.9
+        default: refs/tags/{previous-version}
         description: ''
         name: MCP_COMMON_SCRIPTS_REFS
         trim: 'false'
     - string:
-        default: 2019.2.9
+        default: "{previous-version}"
         description: 'for formula repo http://mirror.mirantis.com/update/UPDATE_VERSION/salt-formulas/xenial'
         name: UPDATE_VERSION
         trim: 'false'