display polyline while answering quest and remove it on dismisal

Author: Achyut Kumar M

GoInfoGame/GoInfoGame/UI/Map/MapView.swift

@@ -147,11 +147,19 @@ struct MapView: View {
                     shouldShowPolyline = false
                 }
             }
+            .onChange(of: isPresented) { newValue in
+                if !newValue {
+                    shouldShowPolyline = false
+                }
+            }
         .sheet(isPresented: $isPresented, content: {
             let selectedQuest = self.viewModel.selectedQuest
             CustomSheetView {
                 selectedQuest?.parent?.form
             }
+            .onAppear {
+                shouldShowPolyline = true
+            }
             .presentationDetents([.fraction(0.8), .fraction(0.5), .fraction(0.1)], selection: $selectedDetent)
             .scrollDisabled(false)
             .interactiveDismissDisabled()