[CVP] Add force_pull parameter for cvp sanity/spt/stacklight jobs

Related-PROD: PROD-32132

Change-Id: Ie138f4a0eb1f1c47cb1d45681a8627296682bc61
diff --git a/cvp-runner.groovy b/cvp-runner.groovy
index bd2862a..4a4a8b6 100644
--- a/cvp-runner.groovy
+++ b/cvp-runner.groovy
@@ -66,9 +66,10 @@
                     ] + env_vars
 
                 // Generating final config
+                def force_pull = (env.getProperty('force_pull')) ?: false
                 configRun = [
                     'image': IMAGE,
-                    'dockerPull': false,
+                    'dockerPull': force_pull.toBoolean(),
                     'baseRepoPreConfig': false,
                     'dockerMaxCpus': 2,
                     'dockerExtraOpts' : [