Remove the flag to disable Quick View, since it has been released.

chrome/app/chromeos_strings.grdp

Index: chrome/app/chromeos_strings.grdp
diff --git a/chrome/app/chromeos_strings.grdp b/chrome/app/chromeos_strings.grdp
index f8a4775228dd99f24e7f3fc025424263cbdbd61a..9dd821c34a8d821b8ba5ed547f119bb380878d70 100644
--- a/chrome/app/chromeos_strings.grdp
+++ b/chrome/app/chromeos_strings.grdp
@@ -76,12 +76,6 @@ Press any key to continue exploring.
   <message name="IDS_FLAGS_FILE_MANAGER_MTP_DESCRIPTION" desc="Description of the about:flag option for MTP support in file manager.">
     Show MTP devices as a file storage in the file manager.
   </message>
-  <message name="IDS_FLAGS_FILES_QUICK_VIEW_NAME" desc="Name of the feature flag for files app quick view.">
-    Files app quick view
-  </message>
-  <message name="IDS_FLAGS_FILES_QUICK_VIEW_DESCRIPTION" desc="Description for the feature flag for files app quick view.">
-    Flag for files app quick view, which shows quick preview of a file.
-  </message>
   <message name="IDS_FLAGS_VIDEO_PLAYER_CHROMECAST_SUPPORT_NAME" desc="Name of the about:flag option to enable the chromecast support for video app.">
     Experimental Chromecast support for Video Player
   </message>