[ios] Fix TableViewTextLinkCell Label Spacing

- Increases top spacing to 13px
- Decreases bottom spacing to 0px so that the vertical spacing between footnote labels in Clear Browsing Data is not massive.

Screenshots: https://drive.google.com/open?id=12DY7uMoFwu0qpy93N3nUEdsBPIDeaJlQ, https://drive.google.com/open?id=1XARsG_J1dvUu1gSDVBJW4qTfPVMTp8mN

Bug: 863330
Change-Id: I92b7b4d09617353d6ccba088ea8fa3675b32c986
Reviewed-on: https://chromium-review.googlesource.com/1141056
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575851}
3 files changed