Fix/track selection by title (#4129)

* chore(sample): make track selection by title possible

* fix(android): fix test for track selection by title

examples/basic/src/constants/general.ts

@@ -2,13 +2,18 @@ import {
   BufferConfig,
   DRMType,
   ISO639_1,
+  SelectedTrackType,
   TextTrackType,
 } from 'react-native-video';
 import {SampleVideoSource} from '../types';
 import {localeVideo} from '../assets';
 import {Platform} from 'react-native';
 
-export const textTracksSelectionBy = 'index';
+// This constant allows to change how the sample behaves regarding to texts selection.
+// You can change it to change how selector will use tracks information.
+// by default, index will be displayed and index will be applied to selected tracks.
+// You can also use LANGUAGE or TITLE 
+export const textTracksSelectionBy = SelectedTrackType.INDEX;
 
 export const isIos = Platform.OS === 'ios';