ANDROID: uid_sys_stats: rename uid_cputime.c to uid_sys_stats.c

This module tracks cputime and io stats.

Signed-off-by: Jin Qian <jinqian@google.com>
Bug: 34198239
Change-Id: I9ee7d9e915431e0bb714b36b5a2282e1fdcc7342

Conflicts:
	drivers/misc/Kconfig
	drivers/misc/Makefile
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>