Make libhidl_gtest_helper host_supported am: 9392373c1a

Original change: https://android-review.googlesource.com/c/platform/system/libhidl/+/1947313

Change-Id: I7ce2ce5a53c94b51407cac31d10892b31a5c457e
diff --git a/Android.bp b/Android.bp
index 82413b9..9d268f6 100644
--- a/Android.bp
+++ b/Android.bp
@@ -48,6 +48,7 @@
 
 cc_library_headers {
     name: "libhidl_gtest_helper",
+    host_supported: true,
     export_include_dirs: ["gtest_helper"],
 }