Fix the bug net.dns1.pid is same as net.dns2.pid

writePidDns() does not increase the index in case first given dns
already exist in the property.

Change-Id: I1129d0042929b3ee119160e53cae0e4143c7ea88
Signed-off-by: yoonsung.nam <yoonsung.nam@samsung.com>

services/java/com/android/server/ConnectivityService.java

@@ -2179,8 +2179,9 @@ private NetworkStateTracker makeWimaxStateTracker() {
             String dnsString = dns.getHostAddress();
             if (changed || !dnsString.equals(SystemProperties.get("net.dns" + j + "." + pid))) {
                 changed = true;
-                SystemProperties.set("net.dns" + j++ + "." + pid, dns.getHostAddress());
+                SystemProperties.set("net.dns" + j + "." + pid, dns.getHostAddress());
             }
+            j++;
         }
         return changed;
     }