Fix NPE when logging network info for vvm sync.

When the network info for a network can't be fetched on a connectivity
callback, make sure that we don't crash when doing our logging. Null
networks are handled lower in the stack so we don't have to worry about
that.

Bug: 26407644
Change-Id: I3be367d84819f56f82b165fbe92d42dc4c82be16
diff --git a/src/com/android/phone/vvm/omtp/sync/OmtpVvmSyncService.java b/src/com/android/phone/vvm/omtp/sync/OmtpVvmSyncService.java
index 2d4d33c..853ad65 100644
--- a/src/com/android/phone/vvm/omtp/sync/OmtpVvmSyncService.java
+++ b/src/com/android/phone/vvm/omtp/sync/OmtpVvmSyncService.java
@@ -319,7 +319,7 @@
         public void onAvailable(Network network) {
             super.onAvailable(network);
             NetworkInfo info = getConnectivityManager().getNetworkInfo(network);
-            Log.d(TAG, "Network Type: " + info.getTypeName());
+            Log.d(TAG, "Network Type: " + info == null ? "Unknown" : info.getTypeName());
             doSync(network, this, mPhoneAccount, mVoicemail, mAction);
         }