media: add annotations to low-level Media* classes

Also remove explicit runtime exception added to
MediaExtractor.setDataSource, as other methods don't
explicitly declare it.

Includes MediaCodec, Crypto, Drm, Extractor, Muxer, Sync.

Bug: 19756615
Bug: 19967103
Bug: 16906375
Change-Id: If511d85af7f61808fbe63fbdc6e04a3d2e7e262c