use .env for key instead of hardcoding (and rotate key)

lib/common/functions.dart

@@ -1,6 +1,8 @@
 import 'dart:async';
+import 'dart:io' show Platform;
 
 import 'package:flutter/material.dart';
+import 'package:flutter_dotenv/flutter_dotenv.dart';
 
 class Debouncer {
   final int milliseconds;
@@ -17,3 +19,7 @@ class Debouncer {
     _timer?.cancel();
   }
 }
+
+String getGooglePlacesApiKey() {
+  return dotenv.env['GMS_API_KEY'] ?? Platform.environment['GMS_API_KEY'] ?? "";
+}

lib/widgets/custom_dialog_box.dart

@@ -1,9 +1,9 @@
 import 'package:flutter/material.dart';
-import 'package:google_maps_flutter/google_maps_flutter.dart' as gmaps;
 import 'package:flutter_google_places_sdk/flutter_google_places_sdk.dart'
     as places;
 import 'package:wheres_my_sign/common/constants.dart';
 import 'package:smooth_page_indicator/smooth_page_indicator.dart';
+import 'package:wheres_my_sign/common/functions.dart';
 import 'dart:async';
 
 import 'package:wheres_my_sign/models/property.dart';
@@ -35,9 +35,10 @@ class CustomDialogBoxState extends State<CustomDialogBox> {
   final _addressFocusNode = FocusNode();
   Timer? _debouncer;
   List<places.AutocompletePrediction> _predictions = [];
+  String apiKey = getGooglePlacesApiKey();
 
   final places.FlutterGooglePlacesSdk _places = places.FlutterGooglePlacesSdk(
-    'AIzaSyBLSUk32a5qGm3M_n9Yii66I7wi0rmA8oM',
+    getGooglePlacesApiKey(),
   );
 
   late Property property; // Declare property to store final details