Add new tags

The ImageDecoding tag is added to media_profiles.xsd.
The Include, Included and Alias tags are added to media_codecs.xsd. And
the sequence type is changed to choice with min=0 and max=unbounded to
support any order and any number elements.

Bug:128380795
Test: m -j

Change-Id: I9817c4d4b895fcf3a70e074bf27a384fecc43aad