Disable Launcher autocomplete by default

Autocomplete breaks several features (see linked bugs) and a correct
fix requires investigation. Disabling the feature for now.

Bug: 897206, 902558
Test: manual
Change-Id: I54a68a88541fab0e2054349c32c1c1892324f67a
Reviewed-on: https://chromium-review.googlesource.com/c/1332148Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Vladislav Kaznacheev <kaznacheev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607515}

ash/public/cpp/app_list/app_list_features.cc

@@ -35,7 +35,7 @@ const base::Feature kEnableContinueReading{"EnableContinueReading",
 const base::Feature kEnableZeroStateSuggestions{
     "EnableZeroStateSuggestions", base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kEnableAppListSearchAutocomplete{
-    "EnableAppListSearchAutocomplete", base::FEATURE_ENABLED_BY_DEFAULT};
+    "EnableAppListSearchAutocomplete", base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kEnableAppSearchResultRanker{
     "EnableAppSearchResultRanker", base::FEATURE_DISABLED_BY_DEFAULT};