Add merged txt filegroups that depend on the exportable non-updatable txt files

Currently, ther merged txt filegroups are dist'ed as api/*-current.txt
and api/*-removed.txt files during droid dist build.

This change adds additional merged txt filegroup modules
that depend on the non-updatable exportable txt files instead of
the checked in non-updatable txt files (under frameworks/base/core).

These added modules will be dist'ed in droid build, instead of the
currently existing merged txt filegroups.

Test: m nothing && inspect ninja output
Bug: 324254328
Change-Id: Ib0b47ba032a2917d0f2df6ad585d2102d6940c50
diff --git a/api/Android.bp b/api/Android.bp
index 113424f..735d85a 100644
--- a/api/Android.bp
+++ b/api/Android.bp
@@ -374,7 +374,10 @@
     previous_api: ":android.api.public.latest",
     merge_annotations_dirs: ["metalava-manual"],
     defaults_visibility: ["//frameworks/base/api"],
-    visibility: ["//frameworks/base/api"],
+    visibility: [
+        "//frameworks/base/api",
+        "//frameworks/base/core/api",
+    ],
 }
 
 // We resolve dependencies on APIs in modules by depending on a prebuilt of the whole