Revert "lib/string & lib/memcpy: use GNU implementation."

This reverts commit d57ed4b00786c005a09cf66e0be424631e50ae32.
lib: strncpy_from_user && strnlen_user

Change-Id: I60d45f8d25848d32fd7bdbccb424f1862144bdc8
config: strncpy_from_user && strnlen_user
config: enable sched_autogroup
SCHEDULER: Autogroup patch group by current user android UID instead of task ID