[jvm] Gradle cache and parallel builds

Currently, Gradle optimization features `org.gradle.caching` and `org.gradle.parallel` are not enabled.

Is there an issue that prevents to enable them by default?

When I add:
```properties
org.gradle.caching=true
org.gradle.parallel=true
```
and run `gradle clean build`, everything seems to be okay.

Start by reviewing the Gradle build configuration and the effects of enabling org.gradle.caching and org.gradle.parallel. Run `gradle clean build` with both properties enabled, then compare the result with the current defaults; done means confirming whether the build remains reliable and documenting or addressing any blocker.

Scritto dal modello di indicizzazione a partire dal testo della issue.