[iOS][Dark Mode] Fix SendToSelf images not being template images

The images stayed black because they were not template images. As
template images, they are tinted by default in
SettingsImageDetailTextCell, so everything looks fine.

Bug: 1001495
Change-Id: Ie06f62b78e28200a2ec6f963c173687eeaeba5df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1789313
Auto-Submit: Robbie Gibson <rkgibson@google.com>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#694309}

ios/chrome/browser/ui/send_tab_to_self/send_tab_to_self_image_detail_text_item.mm

@@ -29,7 +29,8 @@
   cell.textLabel.text = self.text;
   cell.detailTextLabel.text = self.detailText;
   DCHECK([self.iconImageName length]);
-  cell.image = [UIImage imageNamed:self.iconImageName];
+  cell.image = [[UIImage imageNamed:self.iconImageName]
+      imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
   if (self.selected) {
     cell.accessoryType = UITableViewCellAccessoryCheckmark;
   } else {