Convert version mutator to TransitionMutator

Replace cc.versionMutator with a TransitionMutator.

Bug: 319288033
Flag: EXEMPT refactor
Test: all soong tests pass
Change-Id: Idfd4157115d6f03997a339b43b3da9c2dfe2418d
diff --git a/cc/cc.go b/cc/cc.go
index 740be3a..33f50a2 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -51,7 +51,7 @@
 		ctx.BottomUp("sdk", sdkMutator).Parallel()
 		ctx.BottomUp("llndk", llndkMutator).Parallel()
 		ctx.BottomUp("link", LinkageMutator).Parallel()
-		ctx.BottomUp("version", versionMutator).Parallel()
+		ctx.Transition("version", &versionTransitionMutator{})
 		ctx.BottomUp("begin", BeginMutator).Parallel()
 	})