Skip version mutator for host/ramdisk/recovery

"version" mutator creates stubs variants for "cc" libraries with
"stubs.versions". These stubs are for APEX-APEX or APEX-Platform
boundaries.

For host/ramdisk/recovery variants, stubs are not necessary.

Bug: 153698496
Test: m
Change-Id: Id576c4318d9d69246a4a7e2fb4145d5fd2ab9416

cc/linkable.go

@@ -39,6 +39,8 @@ type LinkableInterface interface {
 	Shared() bool
 	Toc() android.OptionalPath
 
+	Host() bool
+
 	InRamdisk() bool
 	OnlyInRamdisk() bool