Code style improvement

Not a big deal, but for better readability will be great to have a common <VALUE> condition <EXPECTED> structure. Cuz inverted one looks like Yoda's speech.

Author: Vacxe

auth-sample/src/main/java/com/spotify/sdk/android/authentication/sample/MainActivity.java

@@ -128,10 +128,10 @@ protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
         final AuthenticationResponse response = AuthenticationClient.getResponse(resultCode, data);
 
-        if (AUTH_TOKEN_REQUEST_CODE == requestCode) {
+        if (requestCode == AUTH_TOKEN_REQUEST_CODE) {
             mAccessToken = response.getAccessToken();
             updateTokenView();
-        } else if (AUTH_CODE_REQUEST_CODE == requestCode) {
+        } else if (requestCode == AUTH_CODE_REQUEST_CODE) {
             mAccessCode = response.getCode();
             updateCodeView();
         }