feat(ecs): add useLocalStorage support for ManagedInstancesCapacityProvider

[badmintoncryer]

Issue # (if applicable)

N/A

Reason for this change

localStorageConfiguration.useLocalStorage has been available in the L1 CfnCapacityProvider resource since ECS Managed Instances was introduced, but there was no L2 surface for it. Without setting useLocalStorage: true, tasks on Managed Instances would use EBS-backed storage even when the selected instance types have local NVMe storage (instance store).

Description of changes

Adds useLocalStorage?: boolean to ManagedInstancesCapacityProviderProps. When set to true, it maps to localStorageConfiguration.useLocalStorage: true in the synthesized AWS::ECS::CapacityProvider resource, causing ECS to use instance store volumes instead of EBS for task storage.

Validation logic at synthesis time:

useLocalStorage	instanceRequirements.localStorage	Result
true	REQUIRED	No warning
true	INCLUDED	Warning: instances without local storage may be selected
true	EXCLUDED	Hard error: contradictory configuration
true	not set (instanceRequirements provided)	Auto-set to REQUIRED
true	not set (instanceRequirements omitted)	Warning: recommend specifying instanceRequirements

Describe any new or updated permissions being added

None.

Description of how you validated changes

Add both unit and integ test.

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
This security report is NOT a review blocker. Please try merge from main to avoid findings unrelated to the PR.

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	Tests	Passed ✅	Skipped	Failed
Security Guardian Results	48 ran	48 passed

Test	Result
No test annotations available

• View Security Guardian Results

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
This security report is NOT a review blocker. Please try merge from main to avoid findings unrelated to the PR.

---

	Tests	Passed ✅	Skipped	Failed
Security Guardian Results with resolved templates	48 ran	48 passed

Test	Result
No test annotations available

• View Security Guardian Results with resolved templates