Change messaging from handler connection timeouts -> operation timeouts

Instead of having the exception message say the issue is a connection
timeout (which it may not be if the operation just takes a long time
to finish...) change the message to denote that its an operation time
out instead.

Change-Id: Icf20e88ca6b23719b19d98298d7869c783f32f52
Merge "Change messaging from handler connection timeouts -> operation timeouts"