[Provider mode] Carrier item display network type on slice.

Bug: 176871752
Test: (PASS)atest NetworkProviderWorkerTest
(PASS)atest ProviderModelSliceTest
(PASS)atest ProviderModelSliceHelperTest

Change-Id: I79b4c3d45a52f0be0c058044f1d79a7056386193

src/com/android/settings/network/ProviderModelSlice.java

@@ -116,7 +116,9 @@ public class ProviderModelSlice extends WifiSlice {
         // Second section:  Add a carrier item.
         if (hasCarrier) {
             mHelper.updateTelephony();
-            listBuilder.addRow(mHelper.createCarrierRow());
+            listBuilder.addRow(
+                    mHelper.createCarrierRow(
+                            worker != null ? worker.getNetworkTypeDescription() : ""));
             maxListSize--;
         }