Use the bitrise app title to detect staging build promotions

In 6464e3c we misunderstood what the
app slug was and changed the way staging was detected to that quite late
in the process. Turns out the app slug is the unique identifier for the
app (a UUID), not the application name itself which means that those
`run_if` were never evaluated as `true`.

Author: Eijebong

bitrise.yml

@@ -2163,7 +2163,7 @@ workflows:
             envman add --key BITRISE_SCHEME --value FirefoxStaging
             envman add --key EXPORT_METHOD --value development
         run_if: |-
-          {{enveq "BITRISE_APP_SLUG" "staging-firefox-ios"}}
+          {{enveq "BITRISE_APP_TITLE" "staging-firefox-ios"}}
     - script@1.2.1:
         inputs:
         - content: |-
@@ -2175,7 +2175,7 @@ workflows:
             cd -
         title: Set xcodeproj code_sign_identity
         run_if: |-
-          {{enveq "BITRISE_APP_SLUG" "firefox-ios"}}
+          {{enveq "BITRISE_APP_TITLE" "firefox-ios"}}
     - script@1.2.1:
         title: NPM, ContentBlockerGen
         inputs:
@@ -2269,7 +2269,7 @@ workflows:
     - script@1.2.1:
         title: Upload Firefox Prod Beta Symbols
         run_if: |-
-          {{enveq "BITRISE_APP_SLUG" "firefox-ios"}}
+          {{enveq "BITRISE_APP_TITLE" "firefox-ios"}}
         inputs:
         - content: |-
             #!/usr/bin/env bash
@@ -2279,7 +2279,7 @@ workflows:
     - deploy-to-itunesconnect-application-loader@1:
         title: Deploy to AppStoreConnect
         run_if: |-
-          {{enveq "BITRISE_APP_SLUG" "firefox-ios"}}
+          {{enveq "BITRISE_APP_TITLE" "firefox-ios"}}
         inputs:
         - connection: 'off'
         - app_password: "$APPLE_ACCOUNT_PW"