Inconsistent OSGI manifest headers of antlr4-runtime

The current Java org.antlr.antlr4-runtime bundle 4.13.1 (and previous versions starting from 4.10) contain an Import-Package manifest header:

```
Import-Package: org.antlr.v4.gui;resolution:=optional,org.antlr.v4.runti
me,org.antlr.v4.runtime.atn,org.antlr.v4.runtime.dfa,org.antlr.v4.runti
me.misc,org.antlr.v4.runtime.tree,org.antlr.v4.runtime.tree.pattern,org
.antlr.v4.runtime.tree.xpath
```

These are packages that are also exported by this bundle. In an OSGI context (apache felix in my case) with different versions of the org.antlr.antlr4-runtime installed (4.13.1 and 4.9.1 in my case) this leads to errors in dependency resolution.

The Import-Package header should be removed.

Start by locating the Java antlr4-runtime OSGi bundle manifest generation and inspect why its exported packages also appear in Import-Package. Reproduce the dependency-resolution problem with versions 4.13.1 and 4.9.1 in Apache Felix, then verify that the generated manifest no longer contains this Import-Package header.

Written by the indexing model from the issue text.