Remove TODO in statsd AnomalyTracker_test

The underlying item the TODO is referencing had already been resolved
so the test line can be properly added, per the TODO.

Change-Id: I5c16e7ea319bd16e37475381def656b38f39d17f
Fixes: 80095149
Test: make statsd_test && adb sync data && adb shell data/nativetest64/statsd_test/statsd_test