Duplicate named index created on same collection during upgrade from 7.0.3 to 7.0.4

While testing the below scenario, there are duplicate named secondary indexes exist on same collection for different fields. This was a random tests and no clear path is there to reproduce the scenario. I have provide the detailed description of all the operation I have performed during test

Steps to reproduce:

1. Create a 6 node cluster with 7.0.3 - kv-kv-index-index-n1ql-n1ql
2. Load some data say 10k to collection
3. create few indexes on some field

   CREATE INDEX `idx_0_0` ON `test`.`test_scope_1`.`test_collection_1`(`Field_4`)

4. Now run parallel queries to create few indexes and scan request with request_plus consistency while upgrading one node for each of the service. Have an index definition with the different field but same name also.

CREATE INDEX `idx_0_0` ON `test`.`test_scope_1`.`test_collection_1`(`Field_10`)

#  Duplicated named index would be created on the same collection.

1. An explain for below queries refers to same index

   explain select * from `test`.`test_scope_1`.`test_collection_1` where Field_10 is not null;

   [

   {

   "plan": {

   "#operator": "Sequence",

   "~children": [

   {

   "#operator": "IndexScan3",

   "bucket": "test",

   "index": "idx_0_0",

   "index_id": "fb1c043e857b1e47",

   "index_projection": {

   "primary_key": true

   },

   "keyspace": "test_collection_1",

   "namespace": "default",

   "scope": "test_scope_1",

   "spans": [

   {

   "exact": true,

   "range": [

   {

   "inclusion": 0,

   "low": "null"

   }

   ]

   }

   ],

   "using": "gsi"

   },

   {

   "#operator": "Fetch",

   "bucket": "test",

   "keyspace": "test_collection_1",

   "namespace": "default",

   "scope": "test_scope_1"

   },

   {

   "#operator": "Parallel",

   "~child": {

   "#operator": "Sequence",

   "~children": [

   {

   "#operator": "Filter",

   "condition": "((`test_collection_1`.`Field_10`) is not null)"

   },

   {

   "#operator": "InitialProject",

   "result_terms": [

   {

   "expr": "self",

   "star": true

   }

   ]

   }

   ]

   }

   }

   ]

   },

   "text": "select * from `test`.`test_scope_1`.`test_collection_1` where Field_10 is not null;"

   }

   ]

   explain select * from `test`.`test_scope_1`.`test_collection_1` where Field_4 is not null;

   [

   {

   "plan": {

   "#operator": "Sequence",

   "~children": [

   {

   "#operator": "IndexScan3",

   "bucket": "test",

   "index": "idx_0_0",

   "index_id": "5b1de9b8fc2e8e3f",

   "index_projection": {

   "primary_key": true

   },

   "keyspace": "test_collection_1",

   "namespace": "default",

   "scope": "test_scope_1",

   "spans": [

   {

   "exact": true,

   "range": [

   {

   "inclusion": 0,

   "low": "null"

   }

   ]

   }

   ],

   "using": "gsi"

   },

   {

   "#operator": "Fetch",

   "bucket": "test",

   "keyspace": "test_collection_1",

   "namespace": "default",

   "scope": "test_scope_1"

   },

   {

   "#operator": "Parallel",

   "~child": {

   "#operator": "Sequence",

   "~children": [

   {

   "#operator": "Filter",

   "condition": "((`test_collection_1`.`Field_4`) is not null)"

   },

   {

   "#operator": "InitialProject",

   "result_terms": [

   {

   "expr": "self",

   "star": true

   }

   ]

   }

   ]

   }

   }

   ]

   },

   "text": "select * from `test`.`test_scope_1`.`test_collection_1` where Field_4 is not null;"

   }

   ]

Logs are available at - 
https://cb-engineering.s3.amazonaws.com/upgrade_from_7.0.3_to_7.0.4/collectinfo-2022-04-20T062423-ns_1%40172.23.136.107.zip
https://cb-engineering.s3.amazonaws.com/upgrade_from_7.0.3_to_7.0.4/collectinfo-2022-04-20T062423-ns_1%40172.23.136.108.zip
https://cb-engineering.s3.amazonaws.com/upgrade_from_7.0.3_to_7.0.4/collectinfo-2022-04-20T062423-ns_1%40172.23.136.109.zip
https://cb-engineering.s3.amazonaws.com/upgrade_from_7.0.3_to_7.0.4/collectinfo-2022-04-20T062423-ns_1%40172.23.136.110.zip
https://cb-engineering.s3.amazonaws.com/upgrade_from_7.0.3_to_7.0.4/collectinfo-2022-04-20T062423-ns_1%40172.23.136.111.zip
https://cb-engineering.s3.amazonaws.com/upgrade_from_7.0.3_to_7.0.4/collectinfo-2022-04-20T062423-ns_1%40172.23.136.112.zip