Sync with libnativehelper refactoring

jniGetFDFromFileDescriptor() is now a legacy method and moved to a
separate header.

Bug: 151443957
Bug: 158749603
Test: m
Change-Id: Icd06e9a315680c2251dbb9032a904dd6d66aa359
Merged-In: Icd06e9a315680c2251dbb9032a904dd6d66aa359
Exempt-From-Owner-Approval: cherry pick
(cherry picked from commit a5c46825)

Tethering/jni/android_net_util_TetheringUtils.cpp

@@ -18,6 +18,7 @@
 #include <error.h>
 #include <jni.h>
 #include <nativehelper/JNIHelp.h>
+#include <nativehelper/JNIHelpCompat.h>
 #include <nativehelper/ScopedUtfChars.h>
 #include <net/if.h>
 #include <netinet/icmp6.h>