fix keystore location

sidekick/fastlane/Fastfile

@@ -1,26 +1,15 @@
-# This file contains the fastlane.tools configuration
-# You can find the documentation at https://docs.fastlane.tools
-#
-# For a list of all available actions, check out
-#
-#     https://docs.fastlane.tools/actions
-#
-# For a list of all available plugins, check out
-#
-#     https://docs.fastlane.tools/plugins/available-plugins
-#
-
-# Uncomment the line if you want fastlane to automatically update itself
-# update_fastlane
+# fastlane/Fastfile
 
 default_platform(:android)
 
 platform :android do
   desc "Build and upload the app to Google Play Alpha track"
   lane :alpha do
-    # Load keystore properties
+    # Load keystore properties from ~/.android/
     keystore_properties = {}
-    File.open("keystore.properties") do |file|
+    keystore_path = File.expand_path("~/.android/keystore.properties")
+    UI.user_error!("Couldn't find keystore.properties file at #{keystore_path}") unless File.exist?(keystore_path)
+    File.open(keystore_path) do |file|
       file.each_line do |line|
         key, value = line.strip.split('=')
         keystore_properties[key] = value
@@ -43,7 +32,7 @@ platform :android do
     upload_to_play_store(
       track: 'alpha',
       aab: 'app/build/outputs/bundle/release/app-release.aab',
-      json_key: "api.json"
+      json_key: ENV['GOOGLE_PLAY_JSON_KEY']
     )
   end
 end