Deprecate manually setting the payload_content_type and
payload_content_encoding properties of a secret. With this CR a user of
the client only needs to provide the payload, and the client will figure
out what the correct payload_content_type and payload_content_encoding
values should be.
Setting these properties for the user lets us avoid a lot of weird
behaviors such as the one described in Bug #1419166, and also lets us
avoid errors that happen when a user mismatches the payload and an
incorrect content type.
In the interest of backwards compatibility, these properties are still
usable, but will log deprecation warnings. They should be removed in a
future version after current users have had enough time to update their
code bases.
Change-Id: Ibfe3ad42e11bd83c002d0f1b69fb8a323a7b6f3d
Closes-Bug: #1419166
46ef634de8