SurfaceTexture.cpp: use proper nativehelper headers

libnativehelper exports headers under nativehelper. These were
available before incorrectly as global headers in order to give
access to jni.h.

Test: SurfaceTexture.cpp finds headers
Bug: 63762847
Change-Id: I3ec1b888c226c2894649d9f9a8f8203891c1ab02
(cherry picked from commit 849252c4)