Fix NPE in app hibernation dump command.

Incorrectly used index instead of the user id to key into the
SparseArray, causing a null value to be returned instead of the actual
states map for the user. This fixes the issue.

Bug: 199935092
Test: Make a new user; adb shell dumpsys app_hibernation
Change-Id: I3f6fcfbaa7a5e83bcf2be46c9e05e5f2f76adf52
(cherry picked from commit 984ea4250d)

services/core/java/com/android/server/apphibernation/AppHibernationService.java

@@ -696,7 +696,7 @@ public final class AppHibernationService extends SystemService {
                 idpw.print("User Level Hibernation States, ");
                 idpw.printPair("user", userId);
                 idpw.println();
-                Map<String, UserLevelState> stateMap = mUserStates.get(i);
+                Map<String, UserLevelState> stateMap = mUserStates.get(userId);
                 idpw.increaseIndent();
                 for (UserLevelState state : stateMap.values()) {
                     idpw.print(state);