[Findit] Upgrade instance class from F1 to F4.
[Findit] Upgrade instance class from F1 to F4.

This is mainly to increase the memory limit for the app instances to 512MB.

BUG=500992
TBR=qyearsley

Review URL: https://codereview.chromium.org/1185363003

nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra