Add UsageStats CTS tests to AppStandbyController test mapping.

Some UsageStats tests directly test AppStandbyController behavior and
other tests are affected by changes in AppStandbyController. Adding the
UsageStats CTS tests to AppStandbyController's pre and post-submit test
suite should help make sure there are no regressions when we make
changes.

Bug: 146453470
Test: cd into directory and run `atest`
Change-Id: If2109a0a49b1a32460fde965288363e20792c7e1