Splitting this off from the combination issue #3075:

Test permissions behavior.

• (@gnprice) Read through the permissions in our output manifest, and compare to docs to find "dangerous" permissions and other potential pitfalls.
• Test our use of the camera; test scenarios where the user first installs the app, we request permission, where the user then revokes permission, etc. See discussion of dangerous permissions; and more detail here and usage notes here.
• Test our use of the WRITE_EXTERNAL_STORAGE permission, similar to the camera; same docs apply. (For downloading files from the lightbox? Not 100% sure all the places this is used.)
• Test our use of the READ_EXTERNAL_STORAGE permission, similar to the camera; same docs apply. (I think this applies when uploading an existing image. Not 100% sure if there are any other places.)
• Test an install flow for any scary mentions of permissions. E.g., our manifest says we use the SYSTEM_ALERT_WINDOW permission. [That one's gone now, as of the next release after 25.8.122: see Get rid of SYSTEM_ALERT_WINDOW permission in Android manifest #3574 .]