crdb_internal.statement_statistics idle latency invalid for some internal queries

**Describe the problem**
The crdb_internal.statement_statistics idle latency shows a value of `9223372036.854776` if the transaction fingerprint id is the default value. It seems to be using a max value for these scenarios.

Run the following query to see the value.
```sql
select statistics->'statistics'->'idleLat'->>'mean' as idleLate_mean, *
from crdb_internal.statement_statistics
```

Jira issue: CRDB-22536

Epic CRDB-32139