They have also said in the article that the amount that Google claims the DOJ can prove is less than $1 million, so there's a chance this is a very small check from Google's perspective.
Polling the jury pool is not an uncommon practice in high-stakes trials, and I assume that Google has run a poll of the jury pool and found them hostile enough that they are willing to concede to 7-8 figures to avoid a jury getting involved in the decision whether to break Google up.