Move supports :create out of base Flavor model

[agrare]

Currently the supports :create/:delete features are enabled at the base Flavor model, however only Openstack implements these operations

This was added by #15552 along with validate_create_flavor and validate_delete_flavor methods, however the UI doesn't appear to use these and instead just checks ems.class::Flavor.supports?(:create)

The result of this is that you can add a flavor on other Cloud providers such as Amazon and Azure but nothing actually happens when you do so.

Cross Repo Tests: ManageIQ/manageiq-cross_repo-tests#149

Depends on:

• Move supports :create to Openstack provider repo manageiq-providers-openstack#613

Before: Able to get to the Add a Flavor screen with an AWS provider

After: Configuration dropdown is disabled

[agrare]

I'd like to delete validate_create_flavor and validate_delete_flavor but need to do more checking that they aren't used anywhere else

[miq-bot]

Checked commits agrare/manageiq@ecbc1d1~...f3eb604 with ruby 2.5.7, rubocop 0.69.0, haml-lint 0.28.0, and yamllint
1 file checked, 0 offenses detected
Everything looks fine. ⭐

[agrare]

I don't see validate_create_flavor or validate_delete_flavor used anywhere, also running cross repo test of UI and API ManageIQ/manageiq-cross_repo-tests#149

The validations didn't even make any sense, the create_flavor validated that the flavor was connected to an EMS but we are trying to create one.

I'm going to leave these for this bugfix and follow-up later with a refactoring PR to remove the validates_* methods after more time confirming that they aren't used

[simaishi]

Jansa backport details:

$ git log -1
commit 4d39829b12168bb1f58476b458174a87daf3c256
Author: Oleg Barenboim <chessbyte@gmail.com>
Date:   Tue Jul 7 12:24:13 2020 -0400

    Merge pull request #20332 from agrare/move_supports_create_flavor

    Move supports :create out of base Flavor model

    (cherry picked from commit 61df10e30a647d8b55ef4261b8e79058372bd90d)