Compare nightly results up to 7 days in the back (#53065)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/53065

Instead of checking results from the previous day, allow to go back up to 7
days in the past to check for previous runs.

Changelog:
[Internal] [Changed] -

Reviewed By: cipolleschi

Differential Revision: D79568067

fbshipit-source-id: 5d6fac6a06b4e26e52de6fbf6187ec8f8e44e10e