Add new class with APIs of varying visibility

To be used to verify SDK updatability end-to-end.

Bug: 148945438
Test: run SdkExtensionsVerifier
Change-Id: I92e4082496890a1e809671c36bf016a2c52e12d2
diff --git a/api/module-lib-current.txt b/api/module-lib-current.txt
index 8100b07..59aa145 100644
--- a/api/module-lib-current.txt
+++ b/api/module-lib-current.txt
@@ -120,6 +120,14 @@
 
 }
 
+package android.os.ext.test {
+
+  @Deprecated public class Test {
+    method @Deprecated public void testD();
+  }
+
+}
+
 package android.util {
 
   public final class Log {