Make uses_libs and optional_uses_libs configurable

Requested for the mk2bp conversion.

Fixes: 373772769
Test: m nothing --no-skip-soong-tests
Change-Id: I9a36e73f20c73e25b555fb3f0a074b30a548ae50
diff --git a/java/java.go b/java/java.go
index 288042b..8b30262 100644
--- a/java/java.go
+++ b/java/java.go
@@ -3343,7 +3343,7 @@
 	if sdkLib != nil {
 		optional := false
 		if module, ok := ctx.Module().(ModuleWithUsesLibrary); ok {
-			if android.InList(*sdkLib, module.UsesLibrary().usesLibraryProperties.Optional_uses_libs) {
+			if android.InList(*sdkLib, module.UsesLibrary().usesLibraryProperties.Optional_uses_libs.GetOrDefault(ctx, nil)) {
 				optional = true
 			}
 		}