Flip the unbundled switch!

Thanks to a broad effort with contributions from many engineers, we
can now build DocumentsUI against @SystemApi, without using any @hide
APIs.  Woo hoo!

Bug: 110959821
Test: manual
Change-Id: I81bae417f87baef5de34a649c792aecae88f3c57
diff --git a/Android.bp b/Android.bp
index 159c3c7..b166e65 100644
--- a/Android.bp
+++ b/Android.bp
@@ -22,9 +22,7 @@
         proguard_flags_files: ["proguard.flags"],
     },
 
-    // TODO: build against public API as part of b/110959821
-    platform_apis: true,
-    // sdk_version: "current",
+    sdk_version: "system_current",
 }
 
 android_app {