Update netpolicy,bstats tests to not assume DUT will be plugged-in.

Bug: 73037837
Test: atest com.android.server.net.ConnOnActivityStartTest
Test: atest com.android.internal.os.BstatsCpuTimesValidationTest
Change-Id: I0647b6746d7d2cc9e4d24dfb14321f3fa5ac7f1c
2 files changed