Implement IS_READ column in content providers.

Add support for the IS_READ column in the call log and voicemail content
providers. This columns will be used to store whether a call log entry
(currently only voicemail) has been read or otherwise consumed by the
user.

Bug: 5036195
Change-Id: I06840f9820f7d568a738c0307f4294c2b8c66031
5 files changed