Unable to interpolate environment variable on Windows

[andrewtoth]

I get this error:

Caused by: com.crashlytics.tools.android.exception.DistributionException: Crashlytics halted compilation because it can't find the specified file: C:\Program Files (x86)\Jenkins\workspace\Android-Staging-Preview\app\build\outputs\apk\app-staging-debug-v%PLAY_BUILD_NUMBER%.apk

PLAY_BUILD_NUMBER is properly interpolated in the build step bash scripts, but not when uploading through this plugin. I've also tried %{PLAY_BUILD_NUMBER}, $PLAY_BUILD_NUMBER and ${PLAY_BUILD_NUMBER}.