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: If06e9afebf322e5f29cbeb926bf4fb7997d1b9c6
Merged-In: If06e9afebf322e5f29cbeb926bf4fb7997d1b9c6
Exempt-From-Owner-Approval: cherry pick
(cherry picked from commit 087716568596a9183a740d15f179f20ece7e3515)
4 files changed