Automatically turn off Slf4jLogsafeArgs in test code

[iamdanfox]

What happened

I just got an error message from Slf4jLogsafeArgs in conjure-java-runtime tests:

> Task :okhttp-clients:compileTestJava
/Users/dfox/conjure-java-runtime/okhttp-clients/src/test/java/com/palantir/conjure/java/okhttp/FlowControlTest.java:89: warning: [Slf4jLogsafeArgs] slf4j log statement does not use logsafe parameters for arguments [1, 2]
            log.info("Average rate is {}, 1 minute rate is {}", rate.getMeanRate(), rate.getOneMinuteRate());
                    ^
    (see https://github.com/palantir/gradle-baseline#baseline-error-prone-checks)

What should have happened

This should never have wasted my time because it's test-only code so I don't care if it's a logsafe arg.

[stale]

This issue has been automatically marked as stale because it has not been touched in the last 60 days. Please comment if you'd like to keep it open, otherwise it'll be closed in 7 days time.

[iamdanfox]

Let's keep this open