Create a stub for SupervisionService.

Test: adb shell dumpsys supervision
Change-Id: I63ee5b4fa46fac4ac285ea053fb168c24a43063c
Flag: android.app.supervision.flags.supervision_api
Bug: 336297680
Bug: 356895431
Bug: 356895439
diff --git a/services/Android.bp b/services/Android.bp
index 0006455..653cd3c3 100644
--- a/services/Android.bp
+++ b/services/Android.bp
@@ -136,6 +136,7 @@
         ":services.searchui-sources",
         ":services.smartspace-sources",
         ":services.soundtrigger-sources",
+        ":services.supervision-sources",
         ":services.systemcaptions-sources",
         ":services.translation-sources",
         ":services.texttospeech-sources",
@@ -237,6 +238,7 @@
         "services.searchui",
         "services.smartspace",
         "services.soundtrigger",
+        "services.supervision",
         "services.systemcaptions",
         "services.translation",
         "services.texttospeech",