Remove settings encryption of analytics-uuid and anon-tracking-enabled

[dpsutton]

We encrypt some settings settings and not others when encryption is enabled.

Ex:

select * 
from setting 
where key in ('show-homepage-data', 'persisted-model-refresh-cron-schedule')

We should not encrypt analytics-uuid and anon-tracking-enabled.

Marked as P2 but perhaps is a P1 and we want to do this with some speed.

[dpsutton]

Question from slack:

When we get this in, will this make the analytics-uuid unencrypted as soon as someone migrates to the new version then? Or will it stay encrypted for migrating old instances and only entirely new ones will have it unencrypted?

[trinya]

Can we up the priority for this one a bit? We need this to build the report of feature usage by customer, that would help us understand e.g. bumps in contraction and make decisions about pricing / plans.