Fix AppCheck typings error

[hsubox76]

Incorrect typing of activate() params in packages/firebase/index.d.ts is causing users to get Typescript errors when using string or provider arguments.

Fixes #5258

[changeset-bot]

🦋 Changeset detected

Latest commit: f2762ac

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@firebase/app-check	Patch
@firebase/app-check-types	Patch
firebase	Patch
@firebase/rules-unit-testing	Patch

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[github-actions]

Changeset File Check ✅

• No modified packages are missing from the changeset file.
• No changeset formatting errors detected.

[google-oss-bot]

Binary Size Report

Affected SDKs

No changes between base commit (8893c82) and head commit (65fc368).

Test Logs

• Base (8893c822): https://github.com/firebase/firebase-js-sdk/actions/runs/1114310589
• Head (65fc368c): https://github.com/firebase/firebase-js-sdk/actions/runs/1114673713

[google-oss-bot]

Size Analysis Report

Affected Products

No changes between base commit (8893c82) and head commit (65fc368).

Test Logs

• Base (8893c82): https://github.com/firebase/firebase-js-sdk/actions/runs/1114310589
• Head (65fc368): https://github.com/firebase/firebase-js-sdk/actions/runs/1114673713