Dedup prebuilt mutator registration

Test: m checkbuild
Bug: 146540677
Change-Id: I9f8a11adf61fe6f352ec1eabc7c5bac332348ba2
diff --git a/android/prebuilt.go b/android/prebuilt.go
index 0ee1201..2c99f1f 100644
--- a/android/prebuilt.go
+++ b/android/prebuilt.go
@@ -25,6 +25,11 @@
 // This file implements common functionality for handling modules that may exist as prebuilts,
 // source, or both.
 
+func RegisterPrebuiltMutators(ctx RegistrationContext) {
+	ctx.PreArchMutators(RegisterPrebuiltsPreArchMutators)
+	ctx.PostDepsMutators(RegisterPrebuiltsPostDepsMutators)
+}
+
 type prebuiltDependencyTag struct {
 	blueprint.BaseDependencyTag
 }