HLS init segment loads are not reported to MediaSourceEventListener

### [REQUIRED] Issue description
Exoplayer tries lo load chunk by url `/vod/78/video_78.mp4` instead of `video_78.mp4?expires=1562330914&md5=4LMrqMnsIj99n8grOu1C3w` (as stated in playlist) and as a result gets 403 Forbidden.

Also see the next difference (correct uri in onLoadStarted, incorrect - in DefaultHttpDataSource's open):
```
07-04 15:48:35.042 D/EventLogger( 4772): onLoadStarted [0.14, 0.00, window=0, period=0, uri=http://mw.iptv/vod/78/video_78.mp4?expires=1562330914&md5=4LMrqMnsIj99n8grOu1C3w, dataSpec.uri=http://mw.iptv/vod/78/video_78.mp4?expires=1562330914&md5=4LMrqMnsIj99n8grOu1C3w]
07-04 15:48:35.066 D/CustomHttpDataSource( 4772): open dataSpec.uri=http://mw.iptv/vod/78/video_78.mp4
```

### [REQUIRED] Reproduction steps
Play content protected by Axinom DRM.

### [REQUIRED] Link to test content
Sorry, no publicly available link.

### [REQUIRED] A full bug report captured from the device
[bugreport.txt](https://github.com/google/ExoPlayer/files/3359384/bugreport.txt)

### [REQUIRED] Version of ExoPlayer being used
2.10.0

### [REQUIRED] Device(s) and version(s) of Android being used
Android 6.0.1
STB GIEC MP1113 (chip Amlogic s905x)