[iOS][MF] Fix cell with extra constraint

Bug: 845472
Change-Id: Ibdcc5ead0e06decf0fc27914bea6801120cc77a9
Reviewed-on: https://chromium-review.googlesource.com/c/1356980Reviewed-by: Yi Su <mrsuyi@chromium.org>
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612656}

ios/chrome/browser/ui/autofill/manual_fill/action_cell.mm

@@ -89,6 +89,7 @@ static const CGFloat BottomBaseSystemSpacingMultiplier = 1.5;
   [self.titleButton setTitleColor:UIColor.cr_manualFillTintColor
                          forState:UIControlStateNormal];
   self.titleButton.enabled = YES;
+  self.grayLine.hidden = YES;
 }
 
 - (void)setUpWithTitle:(NSString*)title
@@ -113,10 +114,7 @@ static const CGFloat BottomBaseSystemSpacingMultiplier = 1.5;
   [verticalLeadViews addObject:self.titleButton];
 
   if (showSeparator) {
-    [verticalLeadViews addObject:self.grayLine];
     self.grayLine.hidden = NO;
-  } else {
-    self.grayLine.hidden = YES;
   }
 
   self.verticalConstraints =