Add the log at onDataConnectionStateChanged do reset displayInfo

Bug: 157517635
Test: build pass.
Change-Id: I7f987d776a33842e0cff426854da07ee799ae5ca
Merged-In: I7f987d776a33842e0cff426854da07ee799ae5ca

packages/SystemUI/src/com/android/systemui/statusbar/policy/MobileSignalController.java

@@ -652,6 +652,8 @@ public class MobileSignalController extends SignalController<
             }
             mDataState = state;
             if (networkType != mTelephonyDisplayInfo.getNetworkType()) {
+                Log.d(mTag, "onDataConnectionStateChanged:"
+                        + " network type change and reset displayInfo. type=" + networkType);
                 mTelephonyDisplayInfo = new TelephonyDisplayInfo(networkType,
                         TelephonyDisplayInfo.OVERRIDE_NETWORK_TYPE_NONE);
             }