With the roll out of the announcement system, we realized we don't have a good way to test announcements in our beta channel. Suggest we add "-beta" as an option for values in the "platforms" field, and implement display of announcements with that value in the beta versions of the apps.

Basic story:
As a PM (or other announcement user) I want to be able to target the announcments to specific versions (identified by version or build number) and to target only "beta" or "production" users of the app.

Additional (nice to have) stories:

• I also want to be able to target only logged in users, so that I can send announcements only to editors or logged in readers.
• I want to be able to provide text for a negative/destructive button to be shown optionally in the feed card. [see subtask for design]

The endpoint was updated to V2 (see parent ticket) and this has been implemented on Android. Per @Dbrant here are the additional keys for the "must have"

min_version: Minimum app version code for which the announcement should be shown.
max_version: Maximum app version code for which the announcement should be shown.
beta: Whether to show the announcement only on pre-production versions of the app.

And the keys for the "nice to haves":
logged_in: Whether to show the announcement only to logged-in users or not.
negative_text: Label for the "negative" button on the announcement. If this field is not provided, the button is not shown.

Android also added two additional parameters that we don't need to add for iOS related to image height and device sync state.