jni: net.TrafficStats: fix getIfaceStat, have it use the iface.

Missing iface8 in call to parseIfaceStats().

Bug: 8304054
Change-Id: Ibb01d86a0f7241cdd8f23401973840673f847efb

core/jni/android_net_TrafficStats.cpp

@@ -166,7 +166,7 @@ static jlong getIfaceStat(JNIEnv* env, jclass clazz, jstring iface, jint type) {
 
     struct Stats stats;
     memset(&stats, 0, sizeof(Stats));
-    if (parseIfaceStats(NULL, &stats) == 0) {
+    if (parseIfaceStats(iface8.c_str(), &stats) == 0) {
         return getStatsType(&stats, (StatsType) type);
     } else {
         return UNKNOWN;