Use tokenize instead of split

Change-Id: If91eb441f3730d5d39891e3782f4bb9e3af6fab9
diff --git a/docker-build-image-pipeline.groovy b/docker-build-image-pipeline.groovy
index 2dc7624..a22439a 100644
--- a/docker-build-image-pipeline.groovy
+++ b/docker-build-image-pipeline.groovy
@@ -22,7 +22,7 @@
 
     def buildArgs = []
     try {
-      buildArgs = IMAGE_BUILD_PARAMS.split(' ')
+      buildArgs = IMAGE_BUILD_PARAMS.tokenize(' ')
     } catch (Throwable e) {
       buildArgs = []
     }