PlayReady broken (in Edge and IE11) since 2.1.2

[Ambroos]

Have you read the FAQ and checked for duplicate issues: yes

What version of Shaka Player are you using: 2.1.2

Can you reproduce the issue with our latest release version: yes

Can you reproduce the issue with the latest code from master: haven't checked (most likely yes)

Are you using the demo app or your own custom app: both

If custom app, can you reproduce the issue using our demo app: yes

What browser and OS are you using: Edge 38, IE11 (latest)

What are the manifest and license server URIs: any PlayReady demo in the Shaka demo page
(you can send the URIs to shaka-player-issues@google.com instead, but please use GitHub and the template for the rest)

What did you do?

• Try to play a PlayReady-protected asset (Axinom and Tears of Steel) on the demo page
• Try to play a PlayReady-protected asset of our own (CastLabs DRMtoday with PlayReady) in our own integration

What did you expect to happen?

• The asset plays

What actually happened?

• The license request is only a single starting XML starting thing (<) and doesn't contain the usual XML/SOAP body. (Both on the demo page and in our own custom integration.)

2.1.1 works fine (custom integration, exact same issue on 2.1.2).

The Chromecast PlayReady does work fine once I manually set the license request header Content-Type to text/xml (is text/html by default for some reason).

[joeyparrish]

Looks like this was caused by PR #815. I mistakenly disabled the relevant tests in c263e0b. I should have realized that we broke it, but I was distrustful of a failure from a third-party server.

I'll see what I can do to fix it. Thanks!

[joeyparrish]

Cherry-picked to v2.1.3.