extensions: fix ExtensionInstalledBubbleModelTest on official bots

This is a speculative fix, waiting for me to figure out how to trybot
it :)

Change-Id: Ibc74b5cb94eff639abe8c4032fda1714445a69b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2062678
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742685}

chrome/browser/ui/extensions/extension_installed_bubble_model_unittest.cc

@@ -96,7 +96,7 @@ TEST_F(ExtensionInstalledBubbleModelTest, OmniboxExtension) {
   // An extension with a regular action and an omnibox keyword...
   auto builder = extensions::ExtensionBuilder("Foo");
   AddOmniboxKeyword(&builder, "fookey");
-  AddRegularAction(&builder);
+  builder.AddFlags(extensions::Extension::WAS_INSTALLED_BY_DEFAULT);
   auto extension = builder.Build();
   extension_service()->AddExtension(extension.get());