Make apex.overrides overridable by override_apex.

Test: apex_test.go
Change-Id: Id47e5e5bec45ec1ada68f9d2d806585c5141a2f9
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 0c6572b..7ac8308 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -3027,12 +3027,14 @@
 			name: "myapex",
 			key: "myapex.key",
 			apps: ["app"],
+			overrides: ["oldapex"],
 		}
 
 		override_apex {
 			name: "override_myapex",
 			base: "myapex",
 			apps: ["override_app"],
+			overrides: ["unknownapex"],
 		}
 
 		apex_key {
@@ -3085,6 +3087,7 @@
 	ensureContains(t, androidMk, "LOCAL_MODULE := override_app.override_myapex")
 	ensureContains(t, androidMk, "LOCAL_MODULE := apex_manifest.pb.override_myapex")
 	ensureContains(t, androidMk, "LOCAL_MODULE_STEM := override_myapex.apex")
+	ensureContains(t, androidMk, "LOCAL_OVERRIDES_MODULES := unknownapex myapex")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := app.myapex")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := override_app.myapex")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := apex_manifest.pb.myapex")