Callback Status MEDIA_STARTING

Please add callback status MEDIA_STARTING to iOS
cordova-plugin-media/src/ios/CDVSound.m: 355

**from**
```
if (!bError) {
//self.currMediaId = audioFile.player.mediaId;
self.currMediaId = mediaId; ...
```

**to**
```
if (!bError) {

[self onStatus:MEDIA_STATE mediaId:mediaId param:@(MEDIA_STARTING)];

//self.currMediaId = audioFile.player.mediaId;
self.currMediaId = mediaId; ...``
```

Start in cordova-plugin-media/src/ios/CDVSound.m around line 355 and inspect the existing status callback flow in the shown block. Done means the iOS implementation emits MEDIA_STARTING through the MEDIA_STATE callback before storing the media ID when startup succeeds.

Written by the indexing model from the issue text.