Move default libnativehelper include to mock dir.

include_deprecated contains all of the
headers that are currently used by libraries without
the "nativehelper/" prefix.

The current count of this is this:
      2 ScopedLocalFrame.h
      4 JniInvocation.h
      4 ScopedBytes.h
      5 AsynchronousCloseMonitor.h
      6 toStringArray.h
      7 ScopedStringChars.h
     38 JniConstants.h
     41 ScopedPrimitiveArray.h
     79 ScopedUtfChars.h
     80 UniquePtr.h
    100 ScopedLocalRef.h
    467 JNIHelp.h

Now we can remove each file from the global header include
on a file by file basis.

Bug: 63762847
Test: libraries still find their headers

Change-Id: I77f1dcff47389bcce55087fe18c46350992e4e06
diff --git a/Android.bp b/Android.bp
index 30a9c59..f2d87a3 100644
--- a/Android.bp
+++ b/Android.bp
@@ -82,9 +82,9 @@
 
 ndk_headers {
     name: "ndk_jni.h",
-    from: "include/nativehelper",
+    from: "include_jni",
     to: "",
-    srcs: ["include/nativehelper/jni.h"],
+    srcs: ["include_jni/jni.h"],
     license: "NOTICE",
 }