OSGI check broken - try to load class BundleEvent always fails

There is a check for running in OSGI env. in ZstdUtils, BrotliUtils, LZMAUtils and XZUtils like this:

static {
    cachedZstdAvailability = CachedAvailability.DONT_CACHE;
    try {
        Class.forName("org.osgi.framework.BundleEvent");
    } catch (final Exception ex) { // NOSONAR
        setCacheZstdAvailablity(true);
    }
}

Loading the class org.osgi.framework.BundleEvent always fails because Import-Package directive for org.osgi.framework is missing in MANIFEST.MF. Or it requires another more sophisticated approaches (https://stackoverflow.com/q/5879040/1061929).

Tested with Eclipse 4.14 (org.eclipse.osgi_3.15.100.v20191114-1701.jar)