Enforce one aconfig_declaration per aconfig package

Bug: b/319121098
Change-Id: Ibe3f1587ed7754f00f464cf385ce51ee9a142412
diff --git a/aconfig/Android.bp b/aconfig/Android.bp
index 3c79f19..402cf16 100644
--- a/aconfig/Android.bp
+++ b/aconfig/Android.bp
@@ -25,6 +25,7 @@
         "aconfig_declarations_test.go",
         "aconfig_values_test.go",
         "aconfig_value_set_test.go",
+        "all_aconfig_declarations_test.go",
     ],
     pluginFor: ["soong_build"],
 }