Increase RAM in manila flavor

Ubuntu Jammy was failing to spawn while using the manila flavor.
It was hitting kernel panic and complaining about memory. That
leads us to increase the flavor to be used in the manila service
image.

Depends-On: Id2d35ce592c73f0c731deb17a5d574f502fe64cb

Change-Id: Idd3e6a6fdb8cf13727cd674c76efd89b3aacfc52

devstack/settings

@@ -135,7 +135,7 @@ MANILA_SERVICE_INSTANCE_PASSWORD=${MANILA_SERVICE_INSTANCE_PASSWORD:-"manila"}
 
 MANILA_SERVICE_VM_FLAVOR_REF=${MANILA_SERVICE_VM_FLAVOR_REF:-100}
 MANILA_SERVICE_VM_FLAVOR_NAME=${MANILA_SERVICE_VM_FLAVOR_NAME:-"manila-service-flavor"}
-MANILA_SERVICE_VM_FLAVOR_RAM=${MANILA_SERVICE_VM_FLAVOR_RAM:-320}
+MANILA_SERVICE_VM_FLAVOR_RAM=${MANILA_SERVICE_VM_FLAVOR_RAM:-512}
 MANILA_SERVICE_VM_FLAVOR_DISK=${MANILA_SERVICE_VM_FLAVOR_DISK:-5}
 MANILA_SERVICE_VM_FLAVOR_VCPUS=${MANILA_SERVICE_VM_FLAVOR_VCPUS:-1}