Make apex_key HostAndDeviceDefault

Since apex_key is used in number of apex_test host_supported modules it
is no longer a device only module.

Test: add new device target and check that the build does not fail
Change-Id: I6402e3b622d22ee0ca0e6af71dfd71a690938e49

apex/key.go

@@ -55,8 +55,7 @@ type apexKeyProperties struct {
 func apexKeyFactory() android.Module {
 	module := &apexKey{}
 	module.AddProperties(&module.properties)
-	// This module is device-only
-	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibCommon)
+	android.InitAndroidArchModule(module, android.HostAndDeviceDefault, android.MultilibCommon)
 	return module
 }