Move to kapt instead of annotationProcessor for paging testapp
Move to kapt instead of annotationProcessor for paging testapp

Fixes the following:
> Configure project :paging:integration-tests:testapp
testapp: 'annotationProcessor' dependencies won't be recognized as kapt annotation processors. Please change the configuration name to 'kapt' for these artifacts: 'androidx.room:room-compiler:2.0.0'.

kapt runs both on kotlin and java.

Test: ./gradlew tasks  -> no longer shows warning
Change-Id: I090f2022e208c45c0c18093aad0ff3c53441690d

AndroidX/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx