BUG 8422: Change tx handlers hard timeout

This makes write-transactions/produce-transactions return an
RpcError upon reaching 2 minutes of waiting after the last
transaction is submitted in case the transactions arent timed out
from the frontend.

Change-Id: I20abbd02ed14e16d9e9a49f935113c0044e7c6d8
Signed-off-by: Tomas Cere <tcere@cisco.com>