GitLab

- Checks if incoming files are store-able in the Downloads section
- Adds a test to get Fail incoming connection due to storage crunch
- PRD for decision on storing in Downloads (go/cros-nearby)

Bug: 1085068
Change-Id: Ibee41fce67d0da5b904112b4b9970215ae874b60
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2336033
Commit-Queue: Himanshu Jaju <himanshujaju@chromium.org>
Reviewed-by: James Vecore <vecore@google.com>
Reviewed-by: Richard Knoll <knollr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799096}