Make URLSpans the same color as regular text in the clipboard overlay

URLSpan link colors are defaulted to invisible, so copying certain
types of text (e.g. emails in Gmail) makes them not show up.

Bug: 238715583
Fix: 238715583
Test: manual, copied the email links in gmail (as in the screenshot
in the bug) and verified that they were visible

Change-Id: I0c74849289ff18146490054eea7a3c9ddc5efc9c