switch secrets to loading from env - towards a more unified way of handling secrets

frontend/android/fastlane/Fastfile

@@ -1,11 +1,8 @@
-# Uncomment the line if you want fastlane to automatically update itself
-# update_fastlane
-
 default_platform(:android)
 
 platform :android do
 
-  desc "Deploy a new version to closed testing"
+  desc "Deploy a new version to closed testing (play store)"
   lane :deploy_testing do
     build_name = ENV["BUILD_NAME"]
     build_number = ENV["BUILD_NUMBER"]
@@ -30,24 +27,26 @@ platform :android do
       )
   end
 
+
   desc "Deploy a new version as a full release"
   lane :deploy_release do
-    gradle(
-      task: "clean assembleRelease",
-      # todo update to a flutter call
-      properties: {
-        # loaded from environment
-        "android.injected.version.name" => ENV["VERSION_NAME"],
-      }
+    build_name = ENV["BUILD_NAME"]
+    build_number = ENV["BUILD_NUMBER"]
+
+    sh(
+      "flutter",
+      "build",
+      "appbundle",
+      "--release",
+      "--build-name=#{build_name}",
+      "--build-number=#{build_number}",
       )
+    
     upload_to_play_store(
-      track: "production",
+      track: 'production',
       skip_upload_apk: true,
       skip_upload_changelogs: true,
       aab: "../build/app/outputs/bundle/release/app-release.aab",
-      # this is the default output of flutter build ... --release
-      # in particular this the build folder lies in the flutter root folder
-      # this is the parent folder for the android folder
-    )
+      )
   end
 end