Make EqualModules a free function.

Bug: 377723687
Test: Unit tests and compare the ninja and mk files generated.
Change-Id: I7e00f09a15f2857f58bea70bcedc4798630a40bc
diff --git a/java/app.go b/java/app.go
index 827b235..c2aa8a4 100644
--- a/java/app.go
+++ b/java/app.go
@@ -1175,7 +1175,7 @@
 			apkInApex := ctx.Module().(android.ApexModule).NotInPlatform()
 			childLinkable, _ := android.OtherModuleProvider(ctx, child, cc.LinkableInfoProvider)
 			parentIsLinkable := false
-			if ctx.EqualModules(ctx.Module(), parent) {
+			if android.EqualModules(ctx.Module(), parent) {
 				parentLinkable, _ := ctx.Module().(cc.LinkableInterface)
 				parentIsLinkable = parentLinkable != nil
 			} else {