Revert "Revert "Fix permadiff that reorders stateful_external_ip blocks on google_compute_instance_group_manager and google_compute_region_instance_group_manager resources""

[SarahFrench]

Reverts #9754

I'm re-introducing the original #9577 PR but changing the test case that's vulnerable to the reordering problem.

compute: fixed a permadiff that reordered `stateful_external_ip` and `stateful_internal_ip` blocks on `google_compute_instance_group_manager` and `google_compute_region_instance_group_manager` resources

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

Terraform GA: Diff ( 4 files changed, 373 insertions(+), 21 deletions(-))
Terraform Beta: Diff ( 4 files changed, 373 insertions(+), 21 deletions(-))

[SarahFrench]

This test failed before because the data in the client library has uncertain order due to being a map's k:v pairs yet the provider converts that data into a slice and tries to preserve an order. The test case has 2 interfaces that aren't present in the config and the new sorting logic only acts to sort interfaces that match those in the config; interfaces not in the config are added in what ever order they come from the client library. If the client library has >1 of those then "the order they come from the client library" can vary due to randomness, which means tests cannot assert an expected order.

Other test cases in this unit test are fine because there's only ever 1 'unexpected' interface appended to the end of the slice.

One solution is to update this test case to only consider 1 interface, or another solution is to order the unexpected interfaces stored in unexpectedIps

[SarahFrench]

I'll add ordering of the unexpectedIps slice (that contains interfaces returned from the API that aren't in the config). This will allow this unit test to assert what data returned from the client library will look like without being affected by the randomness of converting maps to slices.

In a real world scenario, if a user has >1 interfaces that aren't present in their Terraform config they will see a diff in their plan and the order of those new fields might change in repeated plans. If I implemented ordering of unexpectedIps users will benefit by those new fields being displayed in a consistent order.

[modular-magician]

Tests analytics

Total tests: 861
Passed tests 796
Skipped tests: 65
Affected tests: 0

Click here to see the affected service packages

• compute

$\textcolor{green}{\textsf{All tests passed in REPLAYING mode.}}$
View the build log

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

Terraform GA: Diff ( 4 files changed, 399 insertions(+), 21 deletions(-))
Terraform Beta: Diff ( 4 files changed, 399 insertions(+), 21 deletions(-))

[modular-magician]

Tests analytics

Total tests: 861
Passed tests 796
Skipped tests: 65
Affected tests: 0

Click here to see the affected service packages

• compute

$\textcolor{green}{\textsf{All tests passed in REPLAYING mode.}}$
View the build log