Add original mime type to bitmap info.

Change-Id: I9eb8e42852a198ecd7907a383c284e89aa0c6a79
Merge remote-tracking branch 'koush/master' into cm-11.0
Merge branch 'master' of https://github.com/koush/ion

# By Koushik Dutta
# Via Koushik Dutta
* 'master' of https://github.com/koush/ion:
  Add original mime type to bitmap info.