[iOS] Makes bottom toolbar visible when modal view disappears

This Cl makes the bottom toolbar visible when initiating a drag down
to close a modal setting view.

Bug: 1106665
Change-Id: I519fac84a18c36c6838384241af01f1c57a824b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2302633Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Ewann Pellé <ewannpv@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789454}

ios/chrome/browser/ui/settings/settings_root_table_view_controller.mm

@@ -143,7 +143,6 @@ const CGFloat kActivityIndicatorDimensionIPhone = 56;
 
 - (void)viewWillDisappear:(BOOL)animated {
   [super viewWillDisappear:animated];
-  [self.navigationController setToolbarHidden:YES animated:YES];
 }
 
 - (void)setEditing:(BOOL)editing animated:(BOOL)animated {