Add HasMutatorFinished

To enforce that selects are only evaluated after a certain point
in a followup cl.

Bug: 323382414
Test: m nothing --no-skip-soong-tests
Change-Id: Ib215fedb904aa2e5f4d65cfd26a23f527eb4983e

android/testing.go

@@ -1326,6 +1326,10 @@ func (ctx *panickingConfigAndErrorContext) Config() Config {
 	return ctx.ctx.Config()
 }
 
+func (ctx *panickingConfigAndErrorContext) HasMutatorFinished(mutatorName string) bool {
+	return ctx.ctx.HasMutatorFinished(mutatorName)
+}
+
 func PanickingConfigAndErrorContext(ctx *TestContext) ConfigurableEvaluatorContext {
 	return &panickingConfigAndErrorContext{
 		ctx: ctx,