Separate multiple DNS addresses with newlines.

Bug: b/65037256
Bug: 65037256
Test: make -j40 RunSettingsRoboTests
Merged-In: I676b5de60477f7c905b08b8bb361104e5f1e05b9
Merged-In: I61bcfc20d43133c12fb8fe78d7bd968af1ee59eb
Change-Id: I4b0709648f8e236177ea73338cfb0d42a5971c06
(cherry picked from commit 2716e841be)

src/com/android/settings/wifi/details/WifiDetailPreferenceController.java

@@ -419,7 +419,7 @@ public class WifiDetailPreferenceController extends PreferenceController impleme
         String dnsServers = mLinkProperties.getDnsServers().stream()
                 .filter(Inet4Address.class::isInstance)
                 .map(InetAddress::getHostAddress)
-                .collect(Collectors.joining(","));
+                .collect(Collectors.joining("\n"));
 
         // Update UI.
         updatePreference(mIpAddressPref, ipv4Address);