(This is a merge of http://go/wvgerrit/13813)
Removes the OS Version property which was only ever implemented on
Android to appease Netflix and never actually used by them. Adds,
instead, a Widevine library version property. Also adds
implementations of this function for both Android and CE Devices.
For Android, the version number is starting at 3.0.0-android, to
reflect that this is the third major revision of the Widevine CDM in
Android.
For CE Devices, the version number is not changing from its current
value (2.2.0) but is gaining a "-ce" on the end in order to
differentiate it from the Android version number.
Bug: 18376638
Change-Id: Ifb3fa0d62631b45d9e91a6a53bcab3be38763d3a
b0b11bc534