Add CreateAliasVariation to BottomUpMutatorContext

Propagate CreateAliasVariation from Blueprint to Soong.

Bug: 164216768
Test: m checkbuild
Change-Id: I635bf67481092b83a8d26ef1cb06e2e3e21a595f
diff --git a/android/mutator.go b/android/mutator.go
index b70c4ff..40e61de 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -216,6 +216,7 @@
 	ReplaceDependencies(string)
 	ReplaceDependenciesIf(string, blueprint.ReplaceDependencyPredicate)
 	AliasVariation(variationName string)
+	CreateAliasVariation(fromVariationName, toVariationName string)
 }
 
 type bottomUpMutatorContext struct {
@@ -436,3 +437,7 @@
 func (b *bottomUpMutatorContext) AliasVariation(variationName string) {
 	b.bp.AliasVariation(variationName)
 }
+
+func (b *bottomUpMutatorContext) CreateAliasVariation(fromVariationName, toVariationName string) {
+	b.bp.CreateAliasVariation(fromVariationName, toVariationName)
+}