[ios] Fix bottom inset issue in tab grid

Reset insets after changing configuration during a size change.

Bug: 1114134
Change-Id: I3d32d5db03f5c2446830336d07821e325a443d22
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351833Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797260}

ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm

@@ -199,6 +199,7 @@ NSUInteger GetPageIndexFromPage(TabGridPage page) {
     [self scrollToPage:_currentPage animated:NO];
     [self configureViewControllerForCurrentSizeClassesAndPage];
     [self setInsetForRemoteTabs];
+    [self setInsetForGridViews];
   };
   [coordinator animateAlongsideTransition:animate completion:nil];
 }