Add another level to modifyRawOomAdj for BIND_NOT_PERCEPTIBLE services

There is a large gap in modifyRawOomAdj between PERCEPTIBLE_LOW_APP_ADJ
and CACHED_APP_MIN_ADJ. A service that is bound with BIND_NOT_PERCEPTIBLE
and then binds to another process with BIND_ABOVE_CLIENT will be dropped
all the way to the cached state.

Flag: com.android.server.am.add_modify_raw_oom_adj_service_level
Fixes: 374810368
Test: atest MockingOomAdjusterTests
Change-Id: I7d71f52b31a3e0c9ab1f00048cce1667eca66648