Remove CarUserManagerHelper #getCurrentForegroundUserInfo

Also cleaned up getInitialUser() which was not being used.

Bug: 131776619
Test: atest CarServiceUnitTest
Test: atest CarServiceTest
Test: atest CarSettingsRoboTests
Test: adb shell am instrument -w -r -e class
android.platform.test.scenario.multiuser.nonui.SwitchToExistingSecondaryUserBenchmark
android.platform.test.scenario/androidx.test.runner.AndroidJUnitRunner
Change-Id: I7648e1dbe1841dd95bac407b598ca27db0d798d4
diff --git a/libraries/car-helpers/multiuser-helper/src/android/platform/helpers/MultiUserHelper.java b/libraries/car-helpers/multiuser-helper/src/android/platform/helpers/MultiUserHelper.java
index 9ce6e91..5518f4d 100644
--- a/libraries/car-helpers/multiuser-helper/src/android/platform/helpers/MultiUserHelper.java
+++ b/libraries/car-helpers/multiuser-helper/src/android/platform/helpers/MultiUserHelper.java
@@ -140,11 +140,7 @@
     }
 
     public UserInfo getCurrentForegroundUserInfo() {
-        return mUserManagerHelper.getCurrentForegroundUserInfo();
-    }
-
-    public int getInitialUser() {
-        return mUserManagerHelper.getInitialUser();
+        return mUserManager.getUserInfo(ActivityManager.getCurrentUser());
     }
 
     /**