With Gradle you need to have the Android Support Repository and Android Support Library
I was having problems with packaging too, but I realized that I was missing a repository. After having a look at the logs your issue seems the same.
This solved my issue with failed packaging - >
Go to - NVPACK\android-sdk-windows\tools\android.bat
Downloaded/Update Android Support Repository and Android Support Library
It should be at the bottom
Other things to try in case above fails(which it should not)
If you are packaging with a C++ or nativization enabled project. Make sure you have Visual Studio Community 2017 well set up
If not try packaging a blank blueprint project and see if it successfully packages. If yes, then it is some project specific issue.
According to this line
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): FAILURE: Build failed with an exception.
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): * What went wrong:
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): A problem occurred configuring project ':app'.
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): > Could not resolve all dependencies for configuration ':app:_debugApk'.
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): > A problem occurred configuring project ':permission_library'.
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): > You have not accepted the license agreements of the following SDK components:
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): [Android Support Repository].
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): Before building your project, you need to accept the license agreements and complete the installation of the missing components using the Android Studio SDK Manager.
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): Alternatively, to learn how to transfer the license agreements from one workstation to another, go to http://d.android.com/r/studio-ui/export-licenses.html
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): * Try:
UATHelper: Packaging (Android (Multi:ASTC,PVRTC,DXT,ATC,ETC2,ETC1)): Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
I think it will solve your issue