remove workaround for nested PreferenceScreen's

Closes #2208
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Add support for notification reminders.

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Closes #1623
Fixes #323
minor preferences tweaks

1) shorten some summaries
2) add summaries to appearance subscreen
3) move common summary functions to common parent class

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another minor pref tweak for mms fallback

1) fix summary for outgoing sms/mms
2) disable mms option when TS-users is unselected, same as the fallback
   approval option.

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update build tools

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Switch to forked ShortcutBadger.

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whitespace cleanup

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Closes #1779
Enabled audio and video drafts

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Closes #1799
Use betterpicker for HMS timeout.

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Closes #1890
Update min/max fix in shortcutbadger

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Fix user-facing helping term 'insecure' to 'unsecured'.

Insecure implies an uncertainty of intention or confidence.
Unsecured is more specifically addressing the protocol which
wraps the message delivered.

Closes #1811
Reset query string when search is collapsed

Closes #2041
make summary of passphrase timeout translatable
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remove double include of betterpicker in build.gradle
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Added l10n for message details

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Closes #2173
Merge pull request #2212 from agrajaghh/betterpicker_translateable

make summary of passphrase timeout translatable
Support install link

Closes #2001
Fixes #1722
Make message details reflect 24-hour system preference.

Fixes #2150
Closes #2163
Explain size limit for large attachments in toasts.

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Fixes #2100
Closes #2172
streaming media

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