r/aws_amplify_app: fix crash updating auto_branch_creation_config

[jar-b]

Description

The update operation was missing the appropriate checks to ensure nil values were not passed into the expander function.

Relations

Closes #29691

Output from Acceptance Testing

% make testacc PKG=amplify TESTS=TestAccAmplify_serial/App
make: Verifying source code with gofmt...
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go1.22.6 test ./internal/service/amplify/... -v -count 1 -parallel 20 -run='TestAccAmplify_serial/App'  -timeout 360m

--- FAIL: TestAccAmplify_serial (7326.08s)
    --- FAIL: TestAccAmplify_serial/App (7326.08s)
        --- PASS: TestAccAmplify_serial/App/tags (5258.13s)
            --- PASS: TestAccAmplify_serial/App/tags/EmptyTag_OnCreate (292.74s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_providerOnly (311.60s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_nonOverlapping (302.30s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_nullOverlappingResourceTag (282.80s)
            --- PASS: TestAccAmplify_serial/App/tags/basic (310.23s)
            --- PASS: TestAccAmplify_serial/App/tags/EmptyTag_OnUpdate_Add (299.40s)
            --- PASS: TestAccAmplify_serial/App/tags/EmptyTag_OnUpdate_Replace (289.53s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_overlapping (303.28s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_updateToProviderOnly (290.14s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_emptyResourceTag (282.28s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_nullNonOverlappingResourceTag (283.03s)
            --- PASS: TestAccAmplify_serial/App/tags/ComputedTag_OnCreate (293.87s)
            --- PASS: TestAccAmplify_serial/App/tags/null (284.63s)
            --- PASS: TestAccAmplify_serial/App/tags/ComputedTag_OnUpdate_Replace (292.53s)
            --- PASS: TestAccAmplify_serial/App/tags/ComputedTag_OnUpdate_Add (291.90s)
            --- PASS: TestAccAmplify_serial/App/tags/DefaultTags_updateToResourceOnly (288.73s)
            --- PASS: TestAccAmplify_serial/App/tags/AddOnUpdate (289.13s)
        --- FAIL: TestAccAmplify_serial/App/AutoBranchCreationConfig (14.44s)
        --- FAIL: TestAccAmplify_serial/App/BasicAuthCredentials (6.04s)
        --- FAIL: TestAccAmplify_serial/App/EnvironmentVariables (19.97s)
        --- SKIP: TestAccAmplify_serial/App/Repository (0.00s)
        --- PASS: TestAccAmplify_serial/App/basic (280.71s)
        --- PASS: TestAccAmplify_serial/App/BuildSpec (292.99s)
        --- PASS: TestAccAmplify_serial/App/CustomRules (295.51s)
        --- PASS: TestAccAmplify_serial/App/Description (294.85s)
        --- PASS: TestAccAmplify_serial/App/IamServiceRole (296.00s)
        --- PASS: TestAccAmplify_serial/App/Name (287.57s)
        --- PASS: TestAccAmplify_serial/App/disappears (279.85s)
FAIL
FAIL    github.com/hashicorp/terraform-provider-aws/internal/service/amplify    7332.066s

Test failures are pre-existing and present in CI, not a related to this change.

[github-actions]

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[ewbankkit]

LGTM 🚀.

[github-actions]

This functionality has been released in v5.65.0 of the Terraform AWS Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

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