Remove i18n package. Add xml files with strings to flutter assets. Create method for passing localized strings to channel.

pubspec.yaml

@@ -3,8 +3,6 @@ description: A new Flutter project.
 
 dependencies:
   http: '>=0.11.3+12'
-  intl: '>=0.14.0 <0.16.0'
-  intl_translation: '>=0.14.0 <0.16.0'
   sprintf: "^3.0.2"
   path_provider: "^0.2.1+1"
   sqflite: any
@@ -49,6 +47,8 @@ flutter:
     - assets/splash_text.png
     - assets/values-ru/strings.xml
     - assets/values-ua/strings.xml
+    - assets/values-en/strings.xml
+    - assets/values-es/strings.xml
 
   # To add assets from package dependencies, first ensure the asset
   # is in the lib/ directory of the dependency. Then,