[Backlog for Android] Recover draft issues/comments, toggle priorities and milestones

Backlog for Android has the following updates:

Draft issues/comments: A draft of your entries is saved while you are creating issues, editing issues, or making comments. When you return to where you previously left off in the app, a prompt will appear to ask if you wish to recover your previous draft.

Enable milestones, priorities, and versions for Issues: At the project settings, you can choose whether to use milestones, priorities, and versions for your project issues.