Dockerfile: gradle, openssl updates
Dockerfile: gradle, openssl updates

 - Do not install old gradle from apt, install gradle 7.0.2 from sources
 - Build openssl for android using android api 24 compilers
 - openssl android destination folders have the word -android- in their names to avoid confusion

frostwire/frostwire-jlibtorrent,frostwire/frostwire-jlibtorrent,frostwire/frostwire-jlibtorrent