Add cdma_rmnet4 to list of monitored interfaces

Lets the data traffic arrows work on LTE device on 1x,
but also lets telephony monitor for hung radios on 1X.

bug:5531630
Change-Id: I9fa25a5223afaa2e37373668c899ac28a95783fa

Author: Robert Greenwalt

core/jni/android_net_TrafficStats.cpp

@@ -68,6 +68,7 @@ static const char* mobile_iface_list[] = {
     "rmnet1",
     "rmnet2",
     "rmnet3",
+    "cdma_rmnet4",
     "ppp0",
     0
 };