Add "throws IOException" to MediaCodec factory methods

android.media.MediaCodec
(createByCodecName|createDecoderByType|createEncoderByType)
now explicitly throws IOException.

Requires changes to existing code for declaration compatibility.

Bug: 11364276
Change-Id: I105ecb7c4bd49bf803111253cd23bab161c988f9
Signed-off-by: Andy Hung <hunga@google.com>