[OOM] Update Cassandra in common with service account

Add service account to requirements.yaml, values.yaml and
deployment/statefulset

Issue-ID: OOM-2703
Signed-off-by: farida azmy <farida.azmy.ext@orange.com>
Co-authored-by: Sylvain Desbureaux <sylvain.desbureaux@orange.com>
Change-Id: I226584b16b2cd1c22a4e71eb48ad95d974640006
3 files changed