Use framework-appsearch-stubs instead of framework-appsearch

The framework.jar now uses framework-appsearch-stubs instead of the
implementation jar framework-appsearch. As a result, it no longer
exports private APIs of framework-appsearch.

This change also refactors the droidstubs module so that we use the
metalava args that are consistent with other stubs.

Bug: b/146218515
Test: m
Change-Id: Ia4ad349bc6297891f7cc23e2528a296d75326c5c
diff --git a/Android.bp b/Android.bp
index 8c85631..abd7d2d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -487,7 +487,7 @@
         "framework-minus-apex",
         "updatable_media_stubs",
         "framework_mediaprovider_stubs",
-        "framework-appsearch", // TODO(b/146218515): should be framework-appsearch-stubs
+        "framework-appsearch-stubs",
         "framework-sdkextensions-stubs-systemapi",
         // TODO(b/146167933): Use framework-statsd-stubs instead.
         "framework-statsd",