Don't reset OOM adjType to cch-empty during recomputing on cycles

The first pass should have an equivalent or better value for it.
During oom recomputing on cycles, if the result of recomputation
is no better than the given 'cachedAdj', its adjType won't be updated,
therefore we'd need to keep its current value as is.

Bug: 156123244
Test: atest MockingOomAdjusterTests
Test: atest FrameworksServicesTests:ActivityManagerServiceTest
Test: atest CtsAppTestCases:ActivityManagerProcessStateTest
Test: Manual - adb shell dumpsys activity oom
Change-Id: Ic4adf76656575926d16c0a037d955795061116e3