Do not set the group and cpuset for the OomAdjuster thread

It'll make it favor using the big cores.

Bug: 182248972
Test: atest CtsAppTestCases
Test: atest MockingOomAdjusterTests
Change-Id: I5920edaca4214b601be2a1aea56e13b2ba860a36

services/core/java/com/android/server/am/OomAdjuster.java

@@ -345,8 +345,6 @@ public final class OomAdjuster {
         final ServiceThread adjusterThread =
                 new ServiceThread(TAG, TOP_APP_PRIORITY_BOOST, false /* allowIo */);
         adjusterThread.start();
-        adjusterThread.getThreadHandler().post(() -> Process.setThreadGroupAndCpuset(
-                adjusterThread.getThreadId(), THREAD_GROUP_TOP_APP));
         return adjusterThread;
     }