Get FSO flags in Android

[Shivansps]

Method to get FSO flags.

The process is more or less like this:

1. KnososNET starts a special android activity to get the flags.
2. FSO export a minimal flags string (json_v2) to the JNI enviroment, without all the SDL, OpenAL, etc stuff so it is not inited and we dont use it here anymore anyway.
3. The java layer exports the string to the C# enviroment.