[web runner][build] Add missing fake packages

US-472 #comment

SCN-1102 #comment

TEST=build succeeds

Change-Id: I626ea2f470f4375a9bb8112ce51b141a1f0f9064
diff --git a/runtime/web_runner_prototype/BUILD.gn b/runtime/web_runner_prototype/BUILD.gn
index 20548a0..e070606 100644
--- a/runtime/web_runner_prototype/BUILD.gn
+++ b/runtime/web_runner_prototype/BUILD.gn
@@ -10,6 +10,11 @@
     deprecated_system_image = true
     # Empty
   }
+
+  package("web_runner_tests") {
+    deprecated_system_image = true
+    # Empty
+  }
 } else {
   source_set("lib") {
     sources = [
diff --git a/runtime/web_view/BUILD.gn b/runtime/web_view/BUILD.gn
index a56d960..b767bc0 100644
--- a/runtime/web_view/BUILD.gn
+++ b/runtime/web_view/BUILD.gn
@@ -23,6 +23,11 @@
     deprecated_system_image = true
     # Empty
   }
+
+  package("web_view_test_package") {
+    deprecated_system_image = true
+    # Empty
+  }
 } else {
   executable("web_view_bin") {
     output_name = "web_view"