refactor: cleanup Dynamic Links example app and integration tests

[Salakar]

Description

• Added CI workflow for Dynamic Links - previously missing.
• Fixed Android build - was looking for e2e dependency but not included on pubspec.yaml. Build would crash previously.
• Fixed iOS build, this was completely broken by fix(dynamic_links,ios): retry handling iOS universal link on network failure #4354.
• Added start of e2e tests using drive package.
• Rewrote the existing integration test (that wasn't being used) to explicitly check parameters.
• Updated Android example app to v2 Flutter embedding.

Related Issues

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Checklist

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• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
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Breaking Change

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• No, this is not a breaking change.