(hopefully last try)
Add new channel arg GRPC_ARG_ABSOLUTE_MAX_METADATA_SIZE as hard limit
for metadata. Change GRPC_ARG_MAX_METADATA_SIZE to be a soft limit.
Behavior is as follows:
Hard limit
(1) if hard limit is explicitly set, this will be used.
(2) if hard limit is not explicitly set, maximum of default and soft
limit * 1.25 (if soft limit is set) will be used.
Soft limit
(1) if soft limit is explicitly set, this will be used.
(2) if soft limit is not explicitly set, maximum of default and hard
limit * 0.8 (if hard limit is set) will be used.
Requests between soft and hard limit will be rejected randomly, requests
above hard limit will be rejected.