Remote schema permission: Unable add permissions for insert_xxx and insert_xxx_one

version: hasura/graphql-engine:v2.0.4

Expected behavior:
allow adding type mutation_root insert_ids insert_ids_one at remote schema permission

Actual behavior:
giving error

error of MRE:
```
Saving permission failed
validation for the given role-based schema failed because expected default value of input value: "update_columns"of input object "ids_on_conflict" to be [] but received
```

MRE:
need two hasura runnings called it A and B, all configuration is done in web ui
A:
run A with env HASURA_GRAPHQL_UNAUTHORIZED_ROLE: anonymous
on A creates a table named ids
add one column name: id type: integer (auto-increment) set it as primary key
at permission allow all permission for anonymous

B:
run B with env HASURA_GRAPHQL_ENABLE_REMOTE_SCHEMA_PERMISSIONS: "true"
add a remote schema connect to A
at permissions allow anonymous to type mutation_root insert_ids
then save