Avoid repeating tests for CreateRunningAccessLogger in proxy_test

[#63074062]

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>
Introduce Null Object for AccessLogger

Avoids leaking knowledge about optionality of logger [#63074062]

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>