Tests fail on local iOS 10

Tests are failing on a local (on Travis, not SauceLabs) iOS 10 device:
https://travis-ci.org/apache/cordova-plugin-media/jobs/547250842

```
**************************************************
* Failures *
**************************************************
1) cordova-plugin-media-tests.tests >> Media actual playback media.spec.19 position should be set properly
- Error: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL. in file:///Users/travis/Library/Developer/CoreSimulator/Devices/62332DED-D4BB-47D1-AF47-E8BE8CF8D7BC/data/Containers/Bundle/Application/C1234FD0-4236-46E4-9B4A-82FCFA776E1B/HelloCordova.app/www/cdvtests/jasmine-2.4.1/jasmine.js (line 1909)
2) cordova-plugin-media-tests.tests >> Media actual playback media.spec.20 duration should be set properly
- media1 = new Media - Error creating Media object. Media file: https://cordova.apache.org/downloads/BlueZedEx.mp3
- Error: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL. in file:///Users/travis/Library/Developer/CoreSimulator/Devices/62332DED-D4BB-47D1-AF47-E8BE8CF8D7BC/data/Containers/Bundle/Application/C1234FD0-4236-46E4-9B4A-82FCFA776E1B/HelloCordova.app/www/cdvtests/jasmine-2.4.1/jasmine.js (line 1909)
- media1 = new Media - Error creating Media object. Media file: https://cordova.apache.org/downloads/BlueZedEx.mp3
3) cordova-plugin-media-tests.tests >> Media actual playback media.spec.21 should be able to resume playback after pause
- media1 = new Media - Error creating Media object. Media file: https://cordova.apache.org/downloads/BlueZedEx.mp3
4) cordova-plugin-media-tests.tests >> Media actual playback media.spec.22 should be able to seek through file
- media1 = new Media - Error creating Media object. Media file: https://cordova.apache.org/downloads/BlueZedEx.mp3
5) cordova-plugin-media-tests.tests >> Media media.spec.24 playback rate should be set properly using setRate
- Expected 0 to be close to 5, 0.
- Expected 0 not to be less than 4.
Executed 27 of 27 specs (5 FAILED) in 4 mins 16 secs.
```

Unfortunately this is blocking https://github.com/apache/cordova-plugin-media/pull/227

Start with Travis job 547250842 and the failing Media specs 19–22 and 24, focusing on the local iOS 10 run rather than SauceLabs. Determine why playback, duration, seeking, and setRate fail, then verify the full 27-spec suite passes so pull request 227 is no longer blocked.

Written by the indexing model from the issue text.