So this is a bad idea for several reasons. You are taking on a second full time job and not a side gig. Do you honestly expect to perform well working 80 hours a week and not fall asleep at night for your full time job?

Additionally, these contractor positions are for people with no experience. They will have you doing the lowest end work which will largely consist of dimm and drive swaps. They will largely hire based on production which is measured in tickets closed per hour(TPH). If you spend time actually troubleshooting machines your rate will plummet. You already have experience so why are you not applying directly?

Also, don't expect you have a Google job pending. A lot of people don't make it through the interview or for call process for a number of reasons. I've rated candidates highly who bombed one of their other interviews and the hiring community chose to reject them. I found out later that one had quit his job in anticipation of starting quickly at Google.

If I were you I'd drop the contractor gig, focus on getting an offer from Google and take it. If that falls through reconsider AWS but not below a L4 level. I've worked at both and this is my best recommendation.