Bump version string for --draft release job

Change-Id: Ifa97d2ee60193fca54f8f33ef855cf1b44fca5be
diff --git a/VERSION b/VERSION
index 3741959..3210742 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.8.27
+1.8.28