restore postinstall script to match master
restore postinstall script to match master

EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase