cv: 4x more RAM & CPU for GAE instances.
cv: 4x more RAM & CPU for GAE instances.

256 MiB leads to regular OOM-ing, which is to be expected with lots of concurrent requests.
For more details, see https://cloud.google.com/appengine/docs/standard

R=qyearsley, yiwzhang

Bug: 1156241
Change-Id: I24cd761190d1d5b04bc8fb2f953d1a6e93c3a0c7
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2697609
Auto-Submit: Andrii Shyshkalov <a30c74fa30536fe7ea81ed6dec202e35e149e1fd@google.com>
Reviewed-by: Jason Clinton <903dc7ec7b1e0549bc200a3278469a1b3add1d8d@chromium.org>
Commit-Queue: Andrii Shyshkalov <a30c74fa30536fe7ea81ed6dec202e35e149e1fd@google.com>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go