[Bug]: Jacoco configuration ignores sourcesets of buildFlavors

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Is there a StackOverflow question about this issue?

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### What happened?

The sourceDirectories configuration in Jacoco.kt seems to be simply setting it from main sourceset and ignores other flavors: `sourceDirectories.setFrom(files("$projectDir/src/main/java", "$projectDir/src/main/kotlin"))`

Instead I think it should be including all sources of the current variant. This can be done in groovy by `variant.sourceSets.java.srcDirs.collect { it.path }.flatten()` but I'm not sure how this can be done in Kotlin which is using a different variant class. I came across this trying to migrate my own project scripts from groovy to kotlin, so any help is appreciated!

### Relevant logcat output

_No response_

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