Add mdns files and unit tests

- Put mdns code to service/mdns because we don't want to impact
  coverage for code that's not yet in use.
- Also fix some lint errors
  - Common typo errors
  - Lines longer than 100 characters
- Update IgnoreUpTo from S to SC_V2 because the tests should be
  ignored until T.

Bug: 232766079
Test: atest FrameworksNetTests
Change-Id: I19af3bf7ae004bd37960f2ad9014cf0c6a804c8d
diff --git a/service/Android.bp b/service/Android.bp
index 45e43bc..c2dbce1 100644
--- a/service/Android.bp
+++ b/service/Android.bp
@@ -181,6 +181,25 @@
     ],
 }
 
+// TODO: Remove this temporary library and put code into module when test coverage is enough.
+java_library {
+    name: "service-mdns",
+    sdk_version: "system_server_current",
+    min_sdk_version: "30",
+    srcs: [
+        "mdns/**/*.java",
+    ],
+    libs: [
+        "framework-annotations-lib",
+        "framework-connectivity-pre-jarjar",
+        "framework-wifi.stubs.module_lib",
+        "service-connectivity-pre-jarjar",
+    ],
+    visibility: [
+        "//packages/modules/Connectivity/tests:__subpackages__",
+    ],
+}
+
 java_library {
     name: "service-connectivity-protos",
     sdk_version: "system_current",