Hello,
you are right, HTTP/S Destinations (SSL client) on AS Java is Java native. Only the ICM server side uses the CommonCryptotLib which supports TLS 1.2.
Currently the Java native implementation supports only TLS 1.0.
But there are plans to implement TLS1.2 support also on AS JAVA client side in the future.
Watch out for the release notes for upcoming patch releases on AS Java.
best regards
Alexander Gimbel