Disable play store app search feature by default.

Since we are using finch to roll out play store app search feature,
we should disable it by default in the client code.

Bug: 996303
Change-Id: Iae9d95ba1666fa76c66a1fcd1a06cae7d6e43571
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1764518Reviewed-by: Vladislav Kaznacheev <kaznacheev@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Jenny Zhang <jennyz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#689526}

ash/public/cpp/app_list/app_list_features.cc

@@ -15,8 +15,8 @@ const base::Feature kEnableAnswerCard{"EnableAnswerCard",
                                       base::FEATURE_ENABLED_BY_DEFAULT};
 const base::Feature kEnableBackgroundBlur{"EnableBackgroundBlur",
                                           base::FEATURE_DISABLED_BY_DEFAULT};
-const base::Feature kEnablePlayStoreAppSearch{"EnablePlayStoreAppSearch",
-                                              base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kEnablePlayStoreAppSearch{
+    "EnablePlayStoreAppSearch", base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kEnableAppDataSearch{"EnableAppDataSearch",
                                          base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kEnableSettingsShortcutSearch{