[Eventing RBAC][UI] Bucket binding dropdown does not include all eligible buckets

STEPS TO REPRODUCE
Create rbac user john having following roles.

Manage Scope Functions [src_bucket:*] , Data Writer [src_bucket:*:*] , Data Writer [metadata:*:*] , Data Writer [dst_bucket:*:*] , Data Reader [src_bucket:*:*] , Data Reader [metadata:*:*] , Data Reader [dst_bucket:*:*] , Data DCP Reader [src_bucket:*:*]

Login as user john.

CASE A
Import following handler having bucket binding to dst_bucket.
https://issues.couchbase.com/secure/attachment/165755/bucket_op-2.json
No bucket is selected from the dropdown for the binding and Next: Add Code is enabled.
Function deployment goes through fine and mutations are processed successfully.

CASE B
Create a new handler via add function dialog. Try to add a bucket alias. dst_bucket is not present in the dropdown menu.