Add container property to aconfig_declarations.

Bug: 311155208
Test: Unit test
Change-Id: I7b187138856d0144203961e82b6dad5e2f8eed9d
diff --git a/cc/Android.bp b/cc/Android.bp
index 77e96db..06e0e5e 100644
--- a/cc/Android.bp
+++ b/cc/Android.bp
@@ -9,6 +9,7 @@
         "blueprint",
         "blueprint-pathtools",
         "soong",
+        "soong-aconfig",
         "soong-aidl-library",
         "soong-android",
         "soong-bazel",