Set Kokoro to 4.14.98 branch

Change-Id: Ifeb331d22dd528097cc96dea8c8160c0a9f18c31
diff --git a/enterprise.xml b/enterprise.xml
index 5436f78..87f95e5 100644
--- a/enterprise.xml
+++ b/enterprise.xml
@@ -89,6 +89,6 @@
       groups="notdefault,internal" remote="coral-internal" />
 
     <project name="kokoro-enterprise" path="kokoro"
-      groups="notdefault,internal" remote="coral-internal" />
+      groups="notdefault,internal" remote="coral-internal" revision="4.14.98" />
     <!-- END closed source repositories -->
 </manifest>