Ensure vendor seapp contexts can't use coredomain

Bug: 280547417
Test: build
Change-Id: Iadff17523767f91f073c6569400e17f1da55fbdc
diff --git a/build/soong/selinux_contexts.go b/build/soong/selinux_contexts.go
index 2416dc9..644a2dd 100644
--- a/build/soong/selinux_contexts.go
+++ b/build/soong/selinux_contexts.go
@@ -434,12 +434,16 @@
 		Text("|| true)") // to make ninja happy even when result is empty
 
 	rule.Temporary(neverallowFile)
-	rule.Command().BuiltTool("checkseapp").
+	checkCmd := rule.Command().BuiltTool("checkseapp").
 		FlagWithInput("-p ", android.PathForModuleSrc(ctx, proptools.String(m.seappProperties.Sepolicy))).
 		FlagWithOutput("-o ", ret).
 		Inputs(inputs).
 		Input(neverallowFile)
 
+	if ctx.SocSpecific() || ctx.DeviceSpecific() {
+		checkCmd.Flag("-c") // check coredomain
+	}
+
 	rule.Build("seapp_contexts", "Building seapp_contexts: "+m.Name())
 	return ret
 }