fix: TextTrackButton on Safari and iOS (#4350)

On Safari and iOS, we use native text tracks, so, during text track
button creation, textTracks() is populated. However, `this.kinds_` isn't
necessarily set and ends up throwing.

Instead, we want to move the fallback for `this.kinds_` from the
constructor and right above the usage of `this.kinds_`.

src/js/control-bar/text-track-controls/text-track-button.js

@@ -26,10 +26,6 @@ class TextTrackButton extends TrackButton {
     options.tracks = player.textTracks();
 
     super(player, options);
-
-    if (!Array.isArray(this.kinds_)) {
-      this.kinds_ = [this.kind_];
-    }
   }
 
   /**
@@ -61,6 +57,10 @@ class TextTrackButton extends TrackButton {
 
     const tracks = this.player_.textTracks();
 
+    if (!Array.isArray(this.kinds_)) {
+      this.kinds_ = [this.kind_];
+    }
+
     for (let i = 0; i < tracks.length; i++) {
       const track = tracks[i];