chore: add iOS integration test CI (#4822)

frontend/scripts/code_generation/language_files/generate_language_files.sh

@@ -1,13 +1,5 @@
 #!/bin/bash
 
-no_pub_get=false
-
-while getopts 's' flag; do
-  case "${flag}" in
-    s) no_pub_get=true ;;
-  esac
-done
-
 echo "Generating language files"
 
 # Store the current working directory
@@ -24,6 +16,9 @@ rm -rf assets/translations/
 mkdir -p assets/translations/
 cp -f ../resources/translations/*.json assets/translations/
 
+# the ci alwayas return a 'null check operator used on a null value' error.
+# so we force to exec the below command to avoid the error.
+# https://github.com/dart-lang/pub/issues/3314
 flutter pub get
 flutter packages pub get