Make resource_dirs configurable

Requested by a user.

Fixes: 373742077
Test: m nothing --no-skip-soong-tests
Change-Id: Ia4f09fd7d58eb7296802c05cbb402642a95a25b3
diff --git a/java/app.go b/java/app.go
index 6572dbd..94c9e5b 100644
--- a/java/app.go
+++ b/java/app.go
@@ -1361,7 +1361,7 @@
 			Filter_product *string
 			Aaptflags      []string
 			Manifest       *string
-			Resource_dirs  []string
+			Resource_dirs  proptools.Configurable[[]string]
 			Flags_packages []string
 		}{
 			Name:           proptools.StringPtr(rroPackageName),