[iOS][AF] Add bouncing to suggestions

Enable bouncing in autofill suggestions scrollview.

Bug: 876657
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I8bbb27c6c2d567bc41e4931a85cefb97453030c3
Reviewed-on: https://chromium-review.googlesource.com/1184716Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585430}

ios/chrome/browser/autofill/form_suggestion_view.mm

@@ -69,7 +69,6 @@ const CGFloat kSuggestionHorizontalMargin = 6;
 - (void)setupSubviews {
   self.showsVerticalScrollIndicator = NO;
   self.showsHorizontalScrollIndicator = NO;
-  self.bounces = NO;
   self.canCancelContentTouches = YES;
 
   UIStackView* stackView = [[UIStackView alloc] initWithArrangedSubviews:@[]];