[iOS] Fix update constraints in NamedGuide

This CL fixes the logic to update the constraints when using
`constrainedFrame`. Constraints were only set up when the internal
`constrainedFrameView` was created, not every time it was used.

Bug: 1304193
Change-Id: I80ff09130ddefb2c87df268fd2839cca3f4166a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3599028
Auto-Submit: Louis Romero <lpromero@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Louis Romero <lpromero@chromium.org>
Cr-Commit-Position: refs/heads/main@{#996076}
diff --git a/ios/chrome/browser/ui/util/named_guide.mm b/ios/chrome/browser/ui/util/named_guide.mm
index a7ec114..cfcd536 100644
--- a/ios/chrome/browser/ui/util/named_guide.mm
+++ b/ios/chrome/browser/ui/util/named_guide.mm
@@ -136,8 +136,6 @@
   // hierarchy in an effort to minimize additional rendering costs.
   if (_constrainedFrameView)
     [self.owningView insertSubview:_constrainedFrameView atIndex:0];
-
-  [self updateConstraintsWithView:_constrainedFrameView];
 }
 
 #pragma mark - Public
@@ -206,6 +204,7 @@
   }
   self.constrainedFrameView.frame = self.constrainedFrame;
   self.constrainedFrameView.autoresizingMask = self.autoresizingMask;
+  [self updateConstraintsWithView:self.constrainedFrameView];
 }
 
 - (void)checkForInactiveConstraints {