compiler.jar size is 40% larger, includes copy of Apache Ant

According to the message at [1], future versions of Closure Compiler binaries will no longer distributed from https://dl.google.com/closure-compiler/ URLs. When comparing the last published version in that endpoint at [2], with the one from NPM there is a substantial 8.3MB->12MB (40%) increase in the compiler.jar size.

Compare with the following commands:
```
wget https://dl.google.com/closure-compiler/compiler-20200719.tar.gz
tar xvfz compiler-20200719.tar.gz
ls -lah closure-compiler-v20200719.jar # 8.3MB
```
whereas the NPM version
```
npm install --no-bin-links --only=prod google-closure-compiler
ls -lah node_modules/google-closure-compiler-java/compiler.jar # 12MB
```

Is this increase expected?

[1] https://github.com/google/closure-compiler/wiki/Binary-Downloads
[2] https://dl.google.com/closure-compiler/compiler-20200719.zip