Update the Lambda execution time from 5min to 15min

[timoa]

• If this PR is a new feature, reference an issue where a consensus about the design was reached (not necessary for small changes)
• Make sure all of the significant new logic is covered by tests
• Rebase your changes on master so that they can be merged easily
• Make sure all tests and linter rules pass
• If you've changed APIs, update the documentation in README and /api/README