Enable CodeBuild Local Cache

Hi backend folks,

After we split our monorepo to multiple Java repositories, one common report that we get is slow build. It was slower in monorepo, hmm... thinking_face:thinking_face:

I found local CodeBuild cache to be more effective than the S3 counterpart for our backend gradle builds; switching from the latter to the former could reduce the average build time by 30%

So, let's switch to local CodeBuild cache! The steps are

Learn more here,
Thanks