twrpRepacker: override slot back after flashing

and move updating partition details to the function

Change-Id: I6f27ab1191246b6a23e625b0e3459db9024691c7
(cherry picked from commit 0fc1ee2c1ab1775ac5f5115842b4aaea15ec9ad6)
diff --git a/partitionmanager.cpp b/partitionmanager.cpp
index b983e73..4fbd324 100755
--- a/partitionmanager.cpp
+++ b/partitionmanager.cpp
@@ -3094,6 +3094,7 @@
 	LOGINFO("Overriding slot to '%s'\n", Slot.c_str());
 	Active_Slot_Display = Slot;
 	DataManager::SetValue("tw_active_slot", Slot);
+	PartitionManager.Update_System_Details();
 }
 
 void TWPartitionManager::Set_Active_Slot(const string& Slot) {