[TIMOB-20080] Windows: Ti.Media.AudioPlayer background audio for Windows 10

Per thread from [PR 488](https://github.com/appcelerator/titanium_mobile_windows/pull/488) {quote} The feature (AudioCategory::BackgroundCapableMedia) is supported in Windows 10, but is deprecated and there's a document on using background audio (I think using background tasks). I don't think we want to just remove the line in Win10+. We probably want to disable the deprecation warning on Windows 10 for this specific instance until/unless we use the new API/flow for doing the background audio. I'd suggest we turn off the compiler warning for this file (or stifle it in some way) on Win 10 compiles, and open a ticket for replacing the mechanism to use the new API in the future. See https://msdn.microsoft.com/en-us/library/windows/apps/mt282140.aspx and https://social.msdn.microsoft.com/Forums/windowsapps/en-US/46432468-b968-4570-a0ce-48babe838f2d/uwpbackground-audio-with-mft-in-windows-10 {quote}