[Files] Hide media views when file-type filters in Recents is enabled.

When file-type filters in Recents is available, it provides equivalent
functionality with media views and they become redundant.
We can hide media views to save vertical space in directory tree in this
situation.

Bug: 1114721
Change-Id: Id4dd9660634560c71eb1a2a8e62879ad3b5206a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2358937Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Naoki Fukino <fukino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798510}

ui/file_manager/file_manager/foreground/js/navigation_list_model.js

@@ -565,7 +565,7 @@ class NavigationListModel extends cr.EventTarget {
 
     if (this.recentModelItem_) {
       this.navigationItems_.push(this.recentModelItem_);
-      if (util.isUnifiedMediaViewEnabled()) {
+      if (util.isUnifiedMediaViewEnabled() && !util.isRecentsFilterEnabled()) {
         // Unified Media View (Images, Videos and Audio).
         this.navigationItems_.push(createFilteredRecentModelItem(
             str('MEDIA_VIEW_AUDIO_ROOT_LABEL'),