This change will publish distributed tracing spans related to
SQL ActiveRecord queries. These queries are unbound, so will still
contain parameter substitution strings in place of actual parameter
values.

This ensures that the SQL strings do not need to be scrubbed, since the
values are not included in the SQL.

More details of rails instrumentation can be found here:
https://guides.rubyonrails.org/active_support_instrumentation.html