Add a linter requiring Nullability Annotations

-This linter only check Java source and its public methods.
-Apply to method return type not primitives or void.
-Apply to method parameters not primitives.

Bug: 307770597
Test: manual test
Change-Id: I372168fb7dbe6c45803994c931bb5d103cf66169

Android.bp

@@ -118,6 +118,10 @@ android_library {
         "telephony-common",
         "ims-common",
     ],
+
+    lint: {
+        extra_check_modules: ["SettingsLibLintChecker"],
+    },
 }
 
 platform_compat_config {