Make the pending top UID's adj value slightly better than

FOREGROUND_APP_ADJ.

In case the pending top UID needs to compete with an already top UID,
it needs a better adj value (which is to minus one).

Bug: 160392839, 155143386, 157180494
Test: b/160392839 CTS: CtsCameraTestCases # android.hardware.multiprocess.camera.cts.CameraEvictionTest#testBasicCamera2ActivityEvictionfailure
Change-Id: Ibe219c3e780603173ad94a16056196d66c95e2a1