Start targetting Java 8 for fakeannotations project
Start targetting Java 8 for fakeannotations project

This matches all the other libraries in androidx

Test: ./gradlew jar (using jdk17) -> no warnings
Change-Id: I4273df7d381b80491b4018d34ed9bd3fa474d1be

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