frameworks/base: 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: modules using frameworks/base find headers
Bug: 63762847
Change-Id: I0f9f231acdebe460f279135462f43d3e32eff64d
diff --git a/core/jni/com_android_internal_os_Zygote.cpp b/core/jni/com_android_internal_os_Zygote.cpp
index cb53106..3887c76 100644
--- a/core/jni/com_android_internal_os_Zygote.cpp
+++ b/core/jni/com_android_internal_os_Zygote.cpp
@@ -54,10 +54,10 @@
 #include <processgroup/processgroup.h>
 
 #include "core_jni_helpers.h"
-#include "JNIHelp.h"
-#include "ScopedLocalRef.h"
-#include "ScopedPrimitiveArray.h"
-#include "ScopedUtfChars.h"
+#include <nativehelper/JNIHelp.h>
+#include <nativehelper/ScopedLocalRef.h>
+#include <nativehelper/ScopedPrimitiveArray.h>
+#include <nativehelper/ScopedUtfChars.h>
 #include "fd_utils.h"
 
 #include "nativebridge/native_bridge.h"