Add RemoteAuthService

Add RemoteAuthService APIs and Stubs (hide) for Settings of D2DA

This CL introduces new SystemApi allow user to discover remote devices
compatible to be registered as remote authenticators via RemoteAuthManager

Design doc: go/remote-auth-manager-fishfood-design

Test: built successfully.
Bug: 290092977
API-Coverage-Bug: 294934095
Change-Id: Iaaae1126065fdc3db469eeb8d85ac654b8199a12
diff --git a/remoteauth/TEST_MAPPING b/remoteauth/TEST_MAPPING
index 5ad8da6..5061319 100644
--- a/remoteauth/TEST_MAPPING
+++ b/remoteauth/TEST_MAPPING
@@ -7,7 +7,7 @@
   // TODO(b/193602229): uncomment once it's supported.
   //"mainline-presubmit": [
   //  {
-  //    "name": "RemoteAuthUnitTests[com.google.android.tethering.apex]"
+  //    "name": "RemoteAuthUnitTests[com.google.android.remoteauth.apex]"
   //  }
   //]
 }