Also automatically unlock if device screenlock was removed.

This solution even works when "don't keep activities" is active

When the user removes the screen lock, the app does not get really
locked. There is no way about getting notified about this. Before users
lock the app without it getting actually locked, we rather remove the
button that was collapsed and not easy to find anyway.

This only shows the settings if a screen lock is available.
If the setting is activated, it shows a drawer item for locking.
Once locked, the screen lock secret needs to be entered to enter the
app again.

First part of #1247

Factor out Android-specific code from TorPlugin

Closes #832

See merge request briar/briar!876

Show names of countries where Tor is blocked

See merge request briar/briar!886

Rename main flavor due to internal conflicts

Closes #1360

See merge request briar/briar!885

Replace assert statements with AssertionErrors

See merge request briar/briar!877

Dark Theme Changes

See merge request briar/briar!884

Use full class names for loggers

See merge request briar/briar!881

This gets rid of all those pesky 9-Patch drawables

Do not show sign-in reminder once PasswordActivity was opened

Closes #47

See merge request briar/briar!879

Move SignIn reminder code into AndroidNotificationManager and don't show reminder once PasswordActivity was opened

Setup UI Tests with Espresso for Automatic Localized Screenshots

Closes #596

See merge request briar/briar!863

This fixes an issue where the build type values were overriding the
flavor values.