Move mixed builds request queuing to final deps

Post deps still supports creating variants, while final deps does not,
this move will ensure all variants are created prior to queuing Bazel
requests.

Test: CI
Change-Id: I92caae009ea3a8769f3f11a9b1ab80de6aac17f3
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index 5804a46..0ed973a 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -29,6 +29,7 @@
 
 	"android/soong/bazel/cquery"
 	"android/soong/shared"
+
 	"github.com/google/blueprint"
 
 	"android/soong/bazel"
@@ -54,7 +55,7 @@
 }
 
 func RegisterMixedBuildsMutator(ctx RegistrationContext) {
-	ctx.PostDepsMutators(func(ctx RegisterMutatorsContext) {
+	ctx.FinalDepsMutators(func(ctx RegisterMutatorsContext) {
 		ctx.BottomUp("mixed_builds_prep", mixedBuildsPrepareMutator).Parallel()
 	})
 }