Big IP ASM and Google CDN

Hi pcsrac , 
I am not aware with your implementation , but I believe you need to remove the TS ASM Cookie , 
So you can check the below Article : 
https://support.f5.com/csp/article/K13693

you will use an iRule to achieve this also I think you need to to do this in responses so you should change the "when HTTP_REQUEST_RELEASE " to be " when HTTP_RESPONSE_RELEASE " to make it triggers in response time instead of Request time. 
you can also take a look in this Article : 
https://community.f5.com/t5/technical-forum/how-to-remove-the-asm-ts-cookie/td-p/129574

I hope it helps you.