[N1QL RBAC Upgrade]Bucket with password not accessible via specific user created for it after upgrade

1. create a 2 node cluster with 4.6.1-3652 with kv,index and n1ql.
2. Do an offline upgrade using the following test:
./testrunner -i query2.ini -t tuqquery.n1ql_upgrade_rbac.UpgradeQueryRBAC.test_offline_upgrade -p skip_load=True -p sasl_buckets=1 -p services_init=kv:index:n1ql-kv:index:n1ql -p nodes_init=2 -p upgrade_to=5.0.0-3015

This test creates 2 buckets. 1 password protected bucket bucket0 and 1 passwordless bucket default with 0 documents.
It then does an offline upgrade to 5.0.0-3015.
https://developer.couchbase.com/documentation/server/current/install/upgrade-offline.html

3. A user bucket0 and a user default is created correctly.
4. Try to issue a query with user bucket0 as:

curl -u bucket0:password http://172.23.106.210:8093/query/service -d 'statement= select * from `bucket0` '

{

"requestID": "7d6a51b8-0e48-40f0-8faf-b3e609a2696a",

"signature": {"*":"*"},

"results": [

],

"errors": [{"code":13014,"msg":"User does not have credentials to access privilege cluster.bucket[bucket0].n1ql.select!execute. Add role Query Select [bucket0] to allow the query to run."}],

"status": "stopped",

"metrics": {"elapsedTime": "6.268682ms","executionTime": "6.168806ms","resultCount": 0,"resultSize": 0,"errorCount": 1}

}

In UI bucket0 is shown as:
bucket0 Generated user for bucket bucket0 Bucket Full Access[bucket0]

Attaching screenshot.