Function glean_ffi::glean_set_experiment_active

#[no_mangle]
pub extern "C" fn glean_set_experiment_active(
    glean_handle: u64, 
    experiment_id: FfiStr, 
    branch: FfiStr, 
    extra_keys: *const *const c_char, 
    extra_values: *const *const c_char, 
    extra_len: i32
)