Move AAF build to Ubuntu 1804

Per Jessica, LF Help Desk, IT-19350

Issue-ID: AAF-1116
Signed-off-by: Instrumental <jgonap@stl.gathman.org>
Change-Id: I50aef6541bf153df1ca2c7fabea3270af34efeea
diff --git a/jjb/aaf/aaf-luaplugin.yaml b/jjb/aaf/aaf-luaplugin.yaml
index 20bf1c8..8d65de8 100644
--- a/jjb/aaf/aaf-luaplugin.yaml
+++ b/jjb/aaf/aaf-luaplugin.yaml
@@ -1,4 +1,5 @@
 ---
+# Note: 202003, LF says ubuntu1604 is deprecated.  Use ubuntu1804 when needed
 - project:
     name: aaf-luaplugin-clm
     project-name: 'aaf-luaplugin'