In the below example code I have clearly described,how you can share your app page url used by Intent in Linkedin.Here I have used putExtra method to add url.And I have also used  activity info and package name .

 private void shareOnlinkedin() {
         Intent linkedinIntent = new Intent(Intent.ACTION_SEND);
         linkedinIntent.setType("text/plain");

         linkedinIntent.putExtra(Intent.EXTRA_TEXT, referralUrl); //here I have added app page url .

        boolean linkedinAppFound = false;     //check app insall in your phone .
        List<ResolveInfo> matches2 = getActivity().getPackageManager()
                .queryIntentActivities(linkedinIntent, 0);

        for (ResolveInfo info : matches2) {
            if (info.activityInfo.packageName.toLowerCase().startsWith(  //added packageName & className
                    "com.linkedin")) {
                linkedinIntent.setPackage(info.activityInfo.packageName);
                linkedinAppFound = true;
                break;
            }
        }

        if (linkedinAppFound) {              
            startActivity(linkedinIntent);

        }
        else
        {
            Toast.makeText(getContext(),"LinkedIn app not Insatlled in your mobile",Toast.LENGTH_LONG).show();

        }
        }