feature: support db import on Android

Billing.Shared/App.cs

@@ -24,8 +24,11 @@ namespace Billing
         private static List<Account> accounts;
         private static List<Category> categories;
 
-        public App()
+        private string initialUrl;
+
+        public App(string url = null)
         {
+            initialUrl = url;
             CurrentCulture = new PlatformCulture();
             InitResources();
 
@@ -36,6 +39,13 @@ namespace Billing
         {
             Helper.Debug($"personal folder: {StoreHelper.PersonalFolder}");
             Helper.Debug($"cache folder: {StoreHelper.CacheFolder}");
+
+            if (initialUrl != null)
+            {
+                var url = initialUrl;
+                initialUrl = null;
+                _ = OpenUrl(url);
+            }
         }
 
         public static async Task InitializeData()
@@ -83,17 +93,25 @@ namespace Billing
             Resources = instance;
         }
 
-        public static bool OpenUrl(Uri uri)
+        public static async Task<bool> OpenUrl(string url)
         {
-            if (uri == null || !uri.IsFile)
+            if (string.IsNullOrEmpty(url))
             {
-                return true;
+                return false;
             }
-            var absolute = uri.AbsolutePath;
-            var url = System.Net.WebUtility.UrlDecode(absolute);
             if (File.Exists(url))
             {
-                Task.Run(async () =>
+                var status = await Permissions.CheckStatusAsync<Permissions.StorageRead>();
+                if (status != PermissionStatus.Disabled &&
+                    status != PermissionStatus.Granted)
+                {
+                    status = await Permissions.RequestAsync<Permissions.StorageRead>();
+                }
+                if (status != PermissionStatus.Granted)
+                {
+                    return false;
+                }
+                _ = Task.Run(async () =>
                 {
                     var result = await StoreHelper.ReloadDatabase(url);
                     if (result)