Clamp ack deadline seconds in subscriber?

[dbolduc]

Determine if we need to clamp the ack deadline seconds in the subscriber between 10 and 600.

The proto documentation says this is the allowable range. The C++ client clamps to this range.

When I try sending the server values outside of this range, nothing errors immediately. Interesting.

I will ask the Pub/Sub folks and report back. If they do not know, the safest course of action is to clamp values.