Enable Gradle build caches

[dkhalanskyjb]

Proposed by @adam-enko

[fzhinkin]

Does it actually improve build times (or anything else)?
If there are no arguments why enabling it could be detrimental, then there should be nothing stopping us from enable it :)

[dkhalanskyjb]

Does it actually improve build times (or anything else)?

Notably. git checkout dkhalanskyjb/enable-build-caches; ./gradlew clean check; ./gradlew clean check; git checkout master; ./gradlew clean check; ./gradlew clean check gives me 3 minutes, 2 minutes, 3 minutes, 3 minutes.

[fzhinkin]

On macOs, build time improvements are even more impressive (6 minutes without build cache, 3 minutes with build cache enabled). Nice!

[dkhalanskyjb]

there should be nothing stopping us from enable it

The main reason would be if the caching mechanism in KGP were broken and failed to get invalidated when changes occurred—which was absolutely the case a few years back at least. I don't know if we consider the issue solved at this point, but we can try and see.