[cloud] Rebase and fix ENI lookup logic to only hit unique ENIs (rebase of #20039) (#23404)
[cloud] Rebase and fix ENI lookup logic to only hit unique ENIs (rebase of #20039) (#23404)

* fix eni lookup logic to update them only when univocally specified (Fixes #19972)

remove redundant eni lookup

* Rename the univocally_find_eni method to uniquely_find_eni

* Idempotency logic minor fixes

* Fixing pep8 reported issues

* Adding a required_together constraint for instance_id and device_index

* Fix ec2_eni private_ip_address matching

* Adding an example of matching via subnet_id and private_ip_address

* Removing the required_together and subnet_id constraints

* Addding some notes to explain the module assumptions

* Implementing Ryan's wording proposal

thaim/ansible,thaim/ansible