server/dbconsole: TestSQLActivityEndpoints failed

server/dbconsole.TestSQLActivityEndpoints [failed](https://mesolite.cluster.engflow.com/invocations/default/c2e7173f-e243-4eac-b84a-af25334ace3d?testReportRun=1&testReportShard=1&testReportAttempt=1#targets-Ly9wa2cvc2VydmVyL2RiY29uc29sZTpkYmNvbnNvbGVfdGVzdA==) on master @ [ca2f114e684924ac8399fb4983cf1b2eaeae659f](https://github.com/cockroachdb/cockroach/commits/ca2f114e684924ac8399fb4983cf1b2eaeae659f):

```
=== RUN TestSQLActivityEndpoints
test_log_scope.go:172: test logs captured to: outputs.zip/logTestSQLActivityEndpoints1621519674
test_log_scope.go:82: use -show-logs to present logs inline
test_server_shim.go:168: automatically injected an external process virtual cluster under test; see comment at top of test_server_shim.go for details.
sql_activity_test.go:797: -- test log scope end --
test logs left over in: outputs.zip/logTestSQLActivityEndpoints1621519674
--- FAIL: TestSQLActivityEndpoints (277.75s)
=== RUN TestSQLActivityEndpoints/half_specified_time_range
sql_activity_test.go:707:
Error Trace: pkg/server/dbconsole/sql_activity_test.go:707
Error: Should NOT be empty, but was []
Test: TestSQLActivityEndpoints/half_specified_time_range
Messages: only-end request must default start and return rows
--- FAIL: TestSQLActivityEndpoints/half_specified_time_range (0.81s)
```

Parameters:
- attempt=1
- race=true
- run=1
- shard=1
Help

See also: [How To Investigate a Go Test Failure \(internal\)](https://cockroachlabs.atlassian.net/l/c/HgfXfJgM)

/cc @cockroachlabs/unowned

[Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-68107

Run server/dbconsole.TestSQLActivityEndpoints, focusing on the half_specified_time_range case, and read pkg/server/dbconsole/sql_activity_test.go around line 707. Use the linked test report and captured logs to trace the SQL activity endpoint behavior. Done means the only-end request defaults its start time and returns rows without the test failing.

Written by the indexing model from the issue text.