Avoid LockSettingsService NPE during CTS due to races around user removal.

Test: atest CtsDevicePolicyManagerTestCases:com.android.cts.devicepolicy.ManagedProfileTest
Fixes: 125421639
Change-Id: Ie015748f4ef54a8de9ad143df2fe1b0f40976f40

services/core/java/com/android/server/locksettings/LockSettingsService.java

@@ -1966,7 +1966,8 @@ public class LockSettingsService extends ILockSettings.Stub {
         } catch (RemoteException ex) {
             Slog.w(TAG, "unable to clear GK secure user id");
         }
-        if (unknownUser || mUserManager.getUserInfo(userId).isManagedProfile()) {
+        UserInfo userInfo = mUserManager.getUserInfo(userId);
+        if (unknownUser || userInfo == null || userInfo.isManagedProfile()) {
             removeKeystoreProfileKey(userId);
         }
     }