Build secrets

These are the secrets used to build and release the app.

• MUSICSEARCH_GHA_HELPER_APP_ID: From GitHub Apps app page (e.g. https://github.com/settings/apps/musicsearch-gha-helper)
• MUSICSEARCH_GHA_HELPER_APP_PRIVATE_KEY:
• ORG_GRADLE_PROJECT_MUSICBRAINZ_CLIENT_ID:
• ORG_GRADLE_PROJECT_MUSICBRAINZ_CLIENT_SECRET:
• ORG_GRADLE_PROJECT_SPOTIFY_CLIENT_ID:
• ORG_GRADLE_PROJECT_SPOTIFY_CLIENT_SECRET:
• PAT: GitHub personal access token with push access (from https://github.com/settings/personal-access-tokens)
• RELEASE_KEYSTORE_JKS_BASE64: The base64 encoding of release-keystore.jks used for publishing our app
• RELEASE_STORE_PASSWORD: The store password to release-keystore.jks
• RELEASE_KEY_PASSWORD: The key password to release-keystore.jks
• GOOGLE_SERVICES_JSON_BASE64: The base64 encoding of google-services.json used for Firebase
• WORKLOAD_IDENTITY_PROVIDER: See https://github.com/google-github-actions/auth#authenticating-via-workload-identity-federation-1
• SERVICE_ACCOUNT: See https://github.com/google-github-actions/auth#authenticating-via-workload-identity-federation-1
• SIGNING_KEY: Conveyor signing key (https://github.com/hydraulic-software/conveyor/blob/master/actions/build/README.md)
• APP_STORE_API_KEY_JSON_BASE64: The base64 encoding of app_store_api_key.json
• GOOGLE_SERVICE_INFO_PLIST_BASE64: The base64 encoding of GoogleService-Info.plist
• MATCH_GIT_BASIC_AUTHORIZATION_BASE64: The base64 encoding of {username}:{PAT} to access private repository with iOS distribution certificates and provisioning profiles
• MATCH_PASSWORD: Fastlane Match password to decrypt the certificates and profiles