Revert "Guard new APIs with __builtin_available"

Revert submission 25624362-persistable-bundle-hack

Reason for revert: Likely culprit for b/317912559

Reverted changes: /q/submissionid:25624362-persistable-bundle-hack
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:027650fb9f4a54a1848f062e9944cd845651208d)
Merged-In: Ifa4d8c849b4f1a7a8ade6592c073dc6c81d0a85c
Change-Id: Ifa4d8c849b4f1a7a8ade6592c073dc6c81d0a85c