OpenSSL support for Android

From COIN-125 and QTBUG-79665 OpenSSL cannot be easily distributed by us because of import/export regulations. So there're these options:

• The user could follow the guide in https://doc.qt.io/qt-5/android-openssl-support.html for how to do add OpenSSL manually.
• Write a new backend that goes via the Java APIs to have OpenSSL support (as mentioned by esabraha in QTBUG-79665)

COIN-125 discusses the topic in more detail.

Plan to handle this: On Qt Creator, the pre-built binaries for OpenSSL from the link will be downloaded, provided with OpenSSL license for the user to accept, then it could be included automatically in relevant projects.