[Provider Model] UI wording change

- Update the summary of Ethernet network
  "To switch networks, disconnect ethernet"

- Update the summary of data usage for non-carrier networks
  "Excludes data used by carrier networks"

- Update the title of Network preferences
  "Network preferences"

- Screenshot:
  https://screenshot.googleplex.com/62URXVwUJbSXKko
  https://screenshot.googleplex.com/AeZDG2HmkmUkeHd

Bug: 178473018
Bug: 178474159
Bug: 178886957
Test: manual test
Change-Id: Id9ed11ed5cc2db329556bf64a13f21999dcdb151

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

@@ -257,7 +257,7 @@ public class ProviderModelSlice extends WifiSlice {
         }
         return rowBuilder
                 .setTitle(mContext.getText(R.string.ethernet))
-                .setSubtitle(mContext.getText(R.string.cannot_switch_networks_while_connected));
+                .setSubtitle(mContext.getText(R.string.to_switch_networks_disconnect_ethernet));
     }
 
     /**