VPLAY-11969 GetTextTrackInfo returns stale information

If the text track is changed without a re-tune then priv_aamps
mPreferredTextTrack, and stream abstractions mTextTrackIndex are not
updated to reflect the current track

The manifest url can be set to null due to an issue with passing the
same string into cache handler methods as multiple params by reference.

The specified language via SetTextTrack() is ignored in perference to the
prefferedTextLanguage list.

Author: DomSyna

fragmentcollector_hls.cpp

@@ -3450,19 +3450,26 @@ AAMPStatusType StreamAbstractionAAMP_HLS::Init(TuneType tuneType)
 				// Generate audio and text track structures
 				PopulateAudioAndTextTracks();
 
-				// Select preferred text track based on user language preferences
-				TextTrackInfo selectedTextTrack;
-				if (SelectPreferredTextTrack(selectedTextTrack))
+				if (aamp->GetPreferredTextTrack().index.empty())
 				{
-					AAMPLOG_INFO("Selected text track - lang:%s, name:%s, rendition:%s",
-								 selectedTextTrack.language.c_str(),
-								 selectedTextTrack.name.c_str(),
-								 selectedTextTrack.rendition.c_str());
-					aamp->SetPreferredTextTrack(std::move(selectedTextTrack));
+					// Select preferred text track based on user language preferences
+					TextTrackInfo selectedTextTrack;
+					if (SelectPreferredTextTrack(selectedTextTrack))
+					{
+						AAMPLOG_INFO("Selected text track - lang:%s, name:%s, rendition:%s",
+									 selectedTextTrack.language.c_str(),
+									 selectedTextTrack.name.c_str(),
+									 selectedTextTrack.rendition.c_str());
+						aamp->SetPreferredTextTrack(std::move(selectedTextTrack));
+					}
+					else
+					{
+						AAMPLOG_WARN("No text track matched user preferences, will use default selection");
+					}
 				}
 				else
 				{
-					AAMPLOG_WARN("No text track matched user preferences, will use default selection");
+					AAMPLOG_INFO("Preferred text track set, so not looking at the list of preferred languages");
 				}
 
 				// Configure Subtitle track for the playback
@@ -7593,6 +7600,7 @@ void StreamAbstractionAAMP_HLS::SelectSubtitleTrack()
 bool StreamAbstractionAAMP_HLS::SelectPreferredTextTrack(TextTrackInfo &selectedTextTrack)
 {
 	std::vector<TextTrackInfo> availableTracks = GetAvailableTextTracks();
+
 	if (availableTracks.empty())
 	{
 		AAMPLOG_WARN("No text tracks available");