Update libnativehelper NDK API

Follows NDK API review of libnativehelper APIs.

(cherry picked from commit f65a2d53a62467462f5d20935cf5ab7ae5b335b8)

Bug: 188067586
Test: m
Merged-In: I7c6f863d02631e16d9f7ab70abb28ebe30a6a68b
Change-Id: I53411093b27af6d9ab158b9927f53bbe17b55146
2 files changed