Clarify UnableToAcquireLockException

[GSmithApps]

Is your feature request related to a problem? Please describe.
This Slack thread: a user had a question about this Exception, and they asked Kapa, and Kapa gave a wrong answer (which Tiho corrected 🙏 ). I suspect Kapa could have given better direction if this exception message contained the info that Tiho corrected with.

Describe the solution you'd like
I ported Tiho's response over to the code and submitted a PR

Describe alternatives you've considered
I recognize that the message I'm putting here is less general than the one that was there previously. If any of it is incorrect in more general scenarios, please correct me 👍 👍

Additional context
None