Finish moving NetworkStats tests to tests/net

Follow-up of commit 4ff3a778abdc16a0a9cc1ee20372afa8bb7f52b0.

Also add @SmallTest annotation to classes moved to tests/net.

Test: no functional change
Bug: 32561414
Change-Id: I0a0e8865d37ba7bae06ce352d3fc385989adc300
6 files changed
tree: 31adffe09c35117db5acee41d95123f792f0c723
  1. core/
  2. services/
  3. tests/