Using jniThrowErrnoException in android_net_NetworkUtils

Since libnativehelper now has an implementation of jniThrowErrnoException,
this method is now used when a system error occurs to avoid code
duplication.

Bug: 180958753
Test: m
Change-Id: I7752fb57e773bc61b47eac8d91695571257ee5b7
1 file changed