Don't update the service b status in cycle-retry of OomAdj

Fix an issue that Service A processes could be marked as Service
B unexpectedly while doing retry in case of cycles.

Also added a unit test case for it.

Bug: 139136939
Test: atest MockingOomAdjusterTests
Change-Id: I4423315d11f2b91b376a5bce260f3a44045139a2