Implement "Always ask for a password" on Android for public links

[schiessle]

Nextcloud knows two settings for passwords and public links: "enforce password" and "always ask for a password". Always ask is basically a suggestion, we ask the user to set a password but they are free to continue without a password.

"Enforce password" works nicely on Android, but not "Always ask for password".

[nextcloud-android-bot]

GitMate.io thinks possibly related issues are #1174 (Android O), #2961 (Asks for Password every few seconds), #2811 (Nextcloud keep asking account password), #1991 (Link password policies behaviour), and #3116 (Android client created multiple app passwords).

[tobiasKaminsky]

So it should just open up a dialog asking for a password, but user is free to also close this dialog?
How is this UX wise handled in webUI?

[joshtrichards]

Fixed in #3989