app_list: Do not show answer card in experiment

We do not show the answer card when we are showing the embedded
Assistant UI.

Bug: 924624
Test: manual
Change-Id: I08fe6bcfd9e3d4e6bee2fb5236a7246405ecb53f
Reviewed-on: https://chromium-review.googlesource.com/c/1481994
Commit-Queue: Tao Wu <wutao@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634865}

ash/public/cpp/app_list/app_list_features.cc

@@ -38,7 +38,9 @@ const base::Feature kEnableEmbeddedAssistantUI{
 
 bool IsAnswerCardEnabled() {
   // Not using local static variable to allow tests to change this value.
-  return base::FeatureList::IsEnabled(kEnableAnswerCard);
+  // Do not show answer card if the embedded Assistant UI is enabled.
+  return base::FeatureList::IsEnabled(kEnableAnswerCard) &&
+         !IsEmbeddedAssistantUIEnabled();
 }
 
 bool IsAppShortcutSearchEnabled() {