Add AutoScalingInstanceRefresh to the UpdatePolicy schema

[ktrysmt]

Issue #, if available: None found (searched open/closed issues and PRs for AutoScalingInstanceRefresh — no hits)

Description of changes:

E3016 reports an error on templates that use the documented AutoScalingInstanceRefresh update policy:

Resources:
  Asg:
    Type: AWS::AutoScaling::AutoScalingGroup
    UpdatePolicy:
      AutoScalingInstanceRefresh:
        Strategy: Rolling
        Preferences:
          MinHealthyPercentage: 0
          InstanceWarmup: 300
          SkipMatching: true
    Properties:
      AutoScalingGroupName: dummy-asg
      MinSize: 1
      MaxSize: 1
      DesiredCapacity: 1
      LaunchTemplate:
        LaunchTemplateId: lt-0123456789abcdef0
        Version: '1'
      VPCZoneIdentifier:
        - subnet-0123456789abcdef0

$ cfn-lint -t min-refresh.yaml
E3016 Additional properties are not allowed ('AutoScalingInstanceRefresh' was unexpected)
min-refresh.yaml:7:7
$ echo $?
2

The template is valid. AutoScalingInstanceRefresh is documented as an UpdatePolicy attribute for
AWS::AutoScaling::AutoScalingGroup, and aws cloudformation validate-template accepts the template
(exit 0).

The cause is that AutoScalingGroupUpdatePolicy in
src/cfnlint/data/schemas/other/resources/update_policy.json sets additionalProperties: false and
enumerates only AutoScalingReplacingUpdate, AutoScalingRollingUpdate and
AutoScalingScheduledAction, so the newer policy falls through to the "unknown key" branch.
UpdatePolicy is a template attribute rather than a resource property, so it is not supplied by the
CloudFormation provider schemas (AutoScalingInstanceRefresh and AutoScalingRollingUpdate both
appear 0 times under data/schemas/providers/) — this file is hand-maintained, and the key was
simply never added.

This change adds AutoScalingInstanceRefresh to AutoScalingGroupUpdatePolicy plus three new
definitions (AutoScalingInstanceRefresh, AutoScalingInstanceRefreshPreferences,
AutoScalingInstanceRefreshAlarmSpecification), transcribed from the AutoScalingInstanceRefresh policy section of the UpdatePolicy attribute reference:

• Strategy — required, Rolling | ReplaceRootVolume
• Preferences.BakeTime / CheckpointDelay — integer, 0–172800
• Preferences.CheckpointPercentages — array of integers
• Preferences.InstanceWarmup — integer
• Preferences.MaxHealthyPercentage — integer, 100–200
• Preferences.MinHealthyPercentage — integer, 0–100
• Preferences.ScaleInProtectedInstances / StandbyInstances — Refresh/Terminate | Ignore | Wait
• Preferences.SkipMatching — boolean
• Preferences.AlarmSpecification.Alarms — array of strings, up to 10 items

Docs: https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-attribute-updatepolicy.html

Validation

Ran the schema through CfnTemplateValidator the same way rules/resources/updatepolicy/Configuration.py
does (strict_types=False, FUNCTIONS in context):

Accepted — the repro above, both examples from the docs page (launch-before-terminate, and
alarm-based rollback with checkpoints and bake time), and Strategy: ReplaceRootVolume.

Still rejected — missing Strategy; Strategy: Bogus; a misspelled preference
(MinHealtyPercentage, which usefully reports Did you mean 'MaxHealthyPercentage'?);
MinHealthyPercentage: 101; MaxHealthyPercentage: 99; and AutoScalingInstanceRefresh on a
non-Auto-Scaling resource.

No regression — the existing "Valid with autoscaling group" combination still passes and
UpdatePolicy: {Foo: Bar} is still rejected.

A positive case covering the full Preferences surface is added to
test/unit/rules/resources/updatepolicy/test_configuration.py.

Deliberately not included

The docs state that AutoScalingInstanceRefresh and AutoScalingRollingUpdate cannot both be
specified on the same Auto Scaling group. That could be expressed as a not/required pair, but I
left it out to keep this change to the missing definitions. Happy to add it here or in a follow-up
if you would prefer it.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

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