check supported protocols and cipher suites from the system when enabling stronger defaults

When StrongSSLSocketFactory blindly enables stronger protocols and cipher suites (e.g. TLS v1.2), systems that do not support these settings fail completely. This leads to major issues in Android versions below Jelly Bean (4.1) when stronger defaults are enabled.

This commit provides a fix that both keeps the prioritization from OnionKitHelper constants in place and also checks the compatibility, without completely breaking connection settings.