Use libnetjniutils for JNI File Descriptor info

Drops use of deprecated API in libnativehelper and uses a common
helper that will be stable across releases.

Bug: 158749603
Test: m
Change-Id: Ic1a1811ffb9a1c207f562a180417e99df31e3502
diff --git a/Tethering/Android.bp b/Tethering/Android.bp
index 23aa7f8..d8557ad 100644
--- a/Tethering/Android.bp
+++ b/Tethering/Android.bp
@@ -67,6 +67,9 @@
         "liblog",
         "libnativehelper_compat_libc++",
     ],
+    static_libs: [
+        "libnetjniutils",
+    ],
 
     // We cannot use plain "libc++" here to link libc++ dynamically because it results in:
     //   java.lang.UnsatisfiedLinkError: dlopen failed: library "libc++_shared.so" not found