CachedAppOptimzer.freezeProcess() should check for null UidRecord

Test: tested on a pixel 6
Bug: 275649588
Change-Id: I18d2401c53191ea412e543dd0964d775f8402208

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

@@ -2056,7 +2056,7 @@ public final class CachedAppOptimizer {
                 frozen = opt.isFrozen();
 
                 final UidRecord uidRec = proc.getUidRecord();
-                if (frozen && uidRec.areAllProcessesFrozen()) {
+                if (frozen && uidRec != null && uidRec.areAllProcessesFrozen()) {
                     uidRec.setFrozen(true);
                     mFreezeHandler.sendMessage(mFreezeHandler.obtainMessage(
                             UID_FROZEN_STATE_CHANGED_MSG, proc));