fix: serverless missing env and no default set

[luislhl]

Motivation

Error:
Cannot resolve serverless.yml: Variables resolution errored with:
  - Cannot resolve variable at "provider.environment.SERVERLESS_DEPLOY_PREFIX": Value not found at "env" source

Acceptance Criteria

• We should set a default for SERVERLESS_DEPLOY_PREFIX, to stop the error in serverless

TODO

• Make sure the build runs for the daemon and update the testnet-india with the new image

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged
• Make sure either the unit tests and/or the QA tests are capable of testing the new features
• Make sure you do not include new dependencies in the project unless strictly necessary and do not include dev-dependencies as production ones. More dependencies increase the possibility of one of them being hijacked and affecting us.