Update post.collect fork with the latest ODK Collect code

[eak24]

We currently run a forked version of the ODK Collect code. However, it was forked over a year ago, and consequently ODK Collect has continued to move forward whereas POST Collect has not rebased/pulled in the new commits. Currently, POST Collect is 963 commits behind ODK and 22 commits ahead, meaning there is a lot of merging to do. The git compare is here. The task is to develop a sustainable system for merging all of the new code in. I just added @dhruvbaijal as a reviewer for the proposed update. This is a good task to check out some of the codebase, see what changes were made, and think about how to make these changes for the long term.

[eak24]

Steps are:

1. Make sure that you can build the current post.collect app
2. try to update the app following this guide
3. Solve merge conflicts.
4. Keep testing on your device.
5. Push.