Revert "Soong support for namespaces"

This reverts commit 63a250a336.

Reason for revert: Some failures:
  namespace_test.go:648: dir1/Blueprints:2:4: a namespace must be the first module in the file 
  such as New Build Breakage: aosp-master/build_test @ 4475274

Change-Id: I1b5db8eb934e51ff22241bfca44199d886b1393b

android/androidmk.go

@@ -159,12 +159,6 @@ func translateAndroidMkModule(ctx SingletonContext, w io.Writer, mod blueprint.M
 		return nil
 	}
 
-	if !amod.commonProperties.NamespaceExportedToMake {
-		// TODO(jeffrygaston) do we want to validate that there are no modules being
-		// exported to Kati that depend on this module?
-		return nil
-	}
-
 	data := provider.AndroidMk()
 
 	if data.Include == "" {