Update to use nativehelper/JNIPlatformHelp.h

Reflects refactoring of JNI helper code that depends on private
methods within libnativehelper.

Bug: 151443957
Test: Treehugger
Change-Id: Id580d7af98d47e84c4491d0471fd09636d0e68b8
Merged-In: Id580d7af98d47e84c4491d0471fd09636d0e68b8
Exempt-From-Owner-Approval: cherry pick
(cherry picked from commit 5f3849bc3f53ef975382175b9f15bd495473b707)
1 file changed