Add com.android.aconfig.annotations to the filegroup used by libcore

aconfig-annotations-lib has a dependency on core_current, but
core_current is using the @FlaggedApi and java_config_library
to flag its APIs.

Use the sources directly to break the circular dependency.
The filegroup is onyl visible to the art/ and libcore/

Bug: 316554963
Test: m droid
Change-Id: Ibf983c2a754249ceb6dbf2a633275f67d6fda666
diff --git a/java/Android.bp b/java/Android.bp
index e31f878..cf3aa95 100644
--- a/java/Android.bp
+++ b/java/Android.bp
@@ -84,6 +84,8 @@
         "android/annotation/FlaggedApi.java",
         "android/annotation/SystemApi.java",
         "android/annotation/TestApi.java",
+        // aconfig annotations
+        "com/android/aconfig/annotations/*.java",
     ],
 
     visibility: [