Fix lint errors in NetworkStatsManagerTest. am: 687c383d78 am: 435f5433f7 am: af2f747a2a

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1967180

Change-Id: I51eb9cc7d3ae116cac5f8ad0cd15083b4e877dc6