About error on shipping.
I do not know if I can contribute, but I was able to solve it.
I will explain how to do it.
1.Activating “gradlew.bat” in C: / Program File / Epic Games / UE_4.18 / Engine / Build / Android / Java / gradle works OK if .gradle is created.
2.However, if it is not created, open “build.gradle”, add “//” before “apply from: 'baseBuildAdditions.gradle” and close it.
3.Once again open “gradlew.bat” and it is OK if the file has been created.
4.Finally, delete “//” in “build.gradle”. You can build with this.