Bp2build-convert droiddoc_exported_dir

Bug: 283299388
Test: `m bp2build` and manual inspection
Change-Id: Ieec2094e446bb030f30103a7e1a06e35cbdcc72e
diff --git a/android/allowlists/allowlists.go b/android/allowlists/allowlists.go
index 483cc84..e954b31 100644
--- a/android/allowlists/allowlists.go
+++ b/android/allowlists/allowlists.go
@@ -903,6 +903,7 @@
 		"aidl_interface_headers",
 		"bpf",
 		"combined_apis",
+		"droiddoc_exported_dir",
 		"license",
 		"linker_config",
 		"java_import",