Quickfix - restore inadvertently overwritten mocks

[kimorris27]

Which issue this PR addresses:

No Jira; just addresses a small issue I encountered in my work.

What this PR does / why we need it:

The commands specified in generate.go in the armmsi package prior to this PR clobbered the contents of one of the mockgen commands, resulting in mocks for only one of the two interfaces being written to the file. This PR has mockgen write each of the interfaces to separate files to restore the mocks that were overwritten.

Test plan for issue:

Ran make generate

Is there any documentation that needs to be updated for this PR?

N/A

How do you know this will function as expected in production?

N/A

[kimorris27]

/azp run ci

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[bitoku]

nit:
You can use the old way (mocks/azureclient/azuresdk/$GOPACKAGE/$GOPACKAGE.go) if you specify the clients in a single line just like this, I guess.

ARO-RP/pkg/util/azureclient/azuresdk/armnetwork/generate.go

Line 7 in d50158c

//go:generate mockgen -destination=../../../../util/mocks/azureclient/azuresdk/$GOPACKAGE/$GOPACKAGE.go github.com/Azure/ARO-RP/pkg/util/azureclient/azuresdk/$GOPACKAGE InterfacesClient,LoadBalancersClient,LoadBalancerBackendAddressPoolsClient,PrivateEndpointsClient,PrivateLinkServicesClient,PublicIPAddressesClient,SecurityGroupsClient,SubnetsClient

[tsatam]

change looks good, checks look good,