service/elbv2: Prevent panics with actions deleted outside Terraform

[bflad]

We will now always sort the API response by Action.Order for reading into the Terraform state. This could potentially cause a plan difference in configurations which list actions out of order so will need a note in the CHANGELOG, however this behavior seems more desirable than switching to schema.TypeSet and removing the ability to omit order from configurations.

Fixes #6171
Fixes #6256

Changes proposed in this pull request:

• Remove sortActionsBasedonTypeinTFFile() which did not account for actions performed outside Terraform and instead sort listener.DefaultActions by Order and rule.Actions by Order
• Add acceptance testing to cover scenario

Previously:

=== CONT  TestAccAWSLBListener_DefaultAction_Order_Recreates
panic: runtime error: index out of range

goroutine 2681 [running]:
github.com/terraform-providers/terraform-provider-aws/aws.sortActionsBasedonTypeinTFFile(0x441e604, 0xe, 0xc00000f5f0, 0x1, 0x1, 0xc00078ddc0, 0x0, 0xc000702ac0, 0x39eee80)
	/Users/bflad/go/src/github.com/terraform-providers/terraform-provider-aws/aws/structure.go:1918 +0x313
github.com/terraform-providers/terraform-provider-aws/aws.resourceAwsLbListenerRead(0xc00078ddc0, 0x3e81980, 0xc0005f6000, 0xc00078ddc0, 0x0)
	/Users/bflad/go/src/github.com/terraform-providers/terraform-provider-aws/aws/resource_aws_lb_listener.go:553 +0x3ff
=== CONT  TestAccAWSLBListenerRule_Action_Order_Recreates
panic: runtime error: index out of range

goroutine 2952 [running]:
github.com/terraform-providers/terraform-provider-aws/aws.sortActionsBasedonTypeinTFFile(0x440a5f0, 0x6, 0xc000612aa0, 0x1, 0x1, 0xc000320000, 0x0, 0xc000cb91f0, 0x1015115)
	/Users/bflad/go/src/github.com/terraform-providers/terraform-provider-aws/aws/structure.go:1918 +0x313
github.com/terraform-providers/terraform-provider-aws/aws.resourceAwsLbListenerRuleRead(0xc000320000, 0x3e82320, 0xc00078c000, 0xc000320000, 0x0)
	/Users/bflad/go/src/github.com/terraform-providers/terraform-provider-aws/aws/resource_aws_lb_listener_rule.go:560 +0x3a2

Output from acceptance testing:

--- PASS: TestAccAWSLBListenerRule_multipleConditionThrowsError (1.88s)
--- PASS: TestAccAWSLBListener_basic (197.21s)
--- PASS: TestAccAWSLBListener_cognito (215.75s)
--- PASS: TestAccAWSLBListenerRule_redirect (229.92s)
--- PASS: TestAccAWSLBListenerRule_basic (231.29s)
--- PASS: TestAccAWSLBListenerRule_cognito (232.58s)
--- PASS: TestAccAWSLBListenerRule_Action_Order_Recreates (238.55s)
--- PASS: TestAccAWSLBListener_DefaultAction_Order (239.66s)
--- PASS: TestAccAWSLBListener_DefaultAction_Order_Recreates (246.70s)
--- PASS: TestAccAWSLBListenerRule_fixedResponse (250.83s)
--- PASS: TestAccAWSLBListenerRule_oidc (251.18s)
--- PASS: TestAccAWSLBListenerRule_changeListenerRuleArnForcesNew (252.49s)
--- PASS: TestAccAWSLBListener_fixedResponse (266.42s)
--- PASS: TestAccAWSLBListener_oidc (284.99s)
--- PASS: TestAccAWSLBListenerRule_updateRulePriority (303.61s)
--- PASS: TestAccAWSLBListener_redirect (308.81s)
--- PASS: TestAccAWSLBListener_https (335.90s)
--- PASS: TestAccAWSLBListenerRule_Action_Order (346.05s)
--- PASS: TestAccAWSLBListenerRule_priority (416.86s)

[mbfrahry]

LGTM

[bflad]

This has been released in version 1.43.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!