[COMMON] Bump ONAP version

Use version 9.0.0 for Istanbul
Also update the doc.

Issue-ID: OOM-1
Signed-off-by: Sylvain Desbureaux <sylvain.desbureaux@orange.com>
Change-Id: I03e11799bf487226784c98b04116f005c89d1e70
diff --git a/kubernetes/common/cassandra/requirements.yaml b/kubernetes/common/cassandra/requirements.yaml
index f2860ff..4189d43 100644
--- a/kubernetes/common/cassandra/requirements.yaml
+++ b/kubernetes/common/cassandra/requirements.yaml
@@ -1,5 +1,6 @@
 # Copyright © 2018 Amdocs, Bell Canada
 # Modifications Copyright © 2018 AT&T
+# Modifications Copyright © 2021 Orange
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,11 +16,11 @@
 
 dependencies:
   - name: common
-    version: ~8.x-0
+    version: ~9.x-0
     repository: 'file://../common'
   - name: repositoryGenerator
-    version: ~8.x-0
+    version: ~9.x-0
     repository: 'file://../repositoryGenerator'
   - name: serviceAccount
-    version: ~8.x-0
+    version: ~9.x-0
     repository: 'file://../serviceAccount'