Indexer creation fails with mixed mode 7.0.x cluster

Steps to reproduce - 

1. Create a mixed mode cluster with 7.0.0-5302 (KV+Query) and 7.0.2-6620 (Indexer) node
2. Add travel-sample bucket
3. Check that the bucket is loaded (but will not load. we have separate ticket for it - MB-48244)
4. Now create index on bucket using below command 

   create index idx on `travel-sample`(age)

   [

   {

   "code": 5000,

   "msg": "GSI CreateIndex() - cause: Index creation for index idx, bucket travel-sample, scope _default, collection _default cannot start. Reason: Fails to create index. There is no available index service that can process this request at this time. Index Service can be in bootstrap, recovery, or non-reachable. Please retry the operation at a later time..",

   "query": "create index idx on `travel-sample`(age);"

   }

   ]

Logs are available at - 
https://cb-engineering.s3.amazonaws.com/MB-48246/48246/collectinfo-2021-08-31T065724-ns_1%40172.23.136.106.zip
https://cb-engineering.s3.amazonaws.com/MB-48246/48246/collectinfo-2021-08-31T065724-ns_1%40172.23.136.196.zip