did you add the lib to the project or tell the IDE where to look for the lib
the include errors means the IDE can not find the header files and it seems you solved that, header files contain the function declaration
unresolved external means the header was found and the IDE knows "xxx" function is there but the linker can not find the actual function body which is defined in the .lib or in this case the .so
I am not sure how to di it in Android Studio but look for a "linker" setting "Gradle" I think its called and make sure it can find the android folder in the platforms folder