Revert "Prevent removing the target user during a user switch."

This reverts commit f9e7fdc38e.

Reason for revert: We need to prevent removing both target and source users during a user switch. b/264999003#comment2
ag/20948004 will be submitted instead of this one.

Change-Id: Ie3bc4c72033fe3d2edaa5800a3c9d445002ef758

services/core/java/com/android/server/pm/UserManagerService.java

@@ -1833,23 +1833,6 @@ public class UserManagerService extends IUserManager.Stub {
         return activityManagerInternal.getCurrentUserId();
     }
 
-    /**
-     * Gets the current user id, or the target user id in case there is a started user switch.
-     *
-     * @return id of current or target foreground user, or {@link UserHandle#USER_NULL} if
-     * {@link ActivityManagerInternal} is not available yet.
-     */
-    @VisibleForTesting
-    int getCurrentOrTargetUserId() {
-        ActivityManagerInternal activityManagerInternal = getActivityManagerInternal();
-        if (activityManagerInternal == null) {
-            Slog.w(LOG_TAG, "getCurrentOrTargetUserId() called too early, ActivityManagerInternal"
-                    + " is not set yet");
-            return UserHandle.USER_NULL;
-        }
-        return activityManagerInternal.getCurrentUser().id;
-    }
-
     /**
      * Gets whether the user is the current foreground user or a started profile of that user.
      *
@@ -5424,7 +5407,8 @@ public class UserManagerService extends IUserManager.Stub {
         final long ident = Binder.clearCallingIdentity();
         try {
             final UserData userData;
-            if (userId == getCurrentOrTargetUserId()) {
+            int currentUser = getCurrentUserId();
+            if (currentUser == userId) {
                 Slog.w(LOG_TAG, "Current user cannot be removed.");
                 return false;
             }

services/tests/servicestests/src/com/android/server/pm/UserLifecycleStressTest.java

@@ -29,7 +29,6 @@ import android.content.pm.UserInfo;
 import android.os.RemoteException;
 import android.os.UserManager;
 import android.platform.test.annotations.Postsubmit;
-import android.provider.Settings;
 import android.util.Log;
 
 import androidx.test.InstrumentationRegistry;
@@ -38,7 +37,6 @@ import androidx.test.runner.AndroidJUnit4;
 
 import com.android.internal.util.FunctionalUtils;
 
-import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -64,22 +62,12 @@ public class UserLifecycleStressTest {
     private Context mContext;
     private UserManager mUserManager;
     private ActivityManager mActivityManager;
-    private String mRemoveGuestOnExitOriginalValue;
 
     @Before
     public void setup() {
         mContext = InstrumentationRegistry.getInstrumentation().getContext();
         mUserManager = mContext.getSystemService(UserManager.class);
         mActivityManager = mContext.getSystemService(ActivityManager.class);
-        mRemoveGuestOnExitOriginalValue = Settings.Global.getString(mContext.getContentResolver(),
-                Settings.Global.REMOVE_GUEST_ON_EXIT);
-
-    }
-
-    @After
-    public void tearDown() {
-        Settings.Global.putString(mContext.getContentResolver(),
-                Settings.Global.REMOVE_GUEST_ON_EXIT, mRemoveGuestOnExitOriginalValue);
     }
 
     /**
@@ -117,9 +105,6 @@ public class UserLifecycleStressTest {
      **/
     @Test
     public void switchToExistingGuestAndStartOverStressTest() throws Exception {
-        Settings.Global.putString(mContext.getContentResolver(),
-                Settings.Global.REMOVE_GUEST_ON_EXIT, "0");
-
         if (ActivityManager.getCurrentUser() != USER_SYSTEM) {
             switchUser(USER_SYSTEM);
         }