Merge branch '2309-troubleshooting-wizard' into 'master'

...java/org/briarproject/briar/android/AndroidComponent.java

...iarproject/briar/android/mailbox/ErrorWizardFragment.java

...rproject/briar/android/mailbox/MailboxStatusFragment.java

.../briarproject/briar/android/mailbox/MailboxViewModel.java

...java/org/briarproject/briar/android/view/BriarButton.java

briar-android/src/main/res/layout/briar_button.xml

...oid/src/main/res/layout/fragment_mailbox_error_wizard.xml

.../main/res/layout/fragment_mailbox_error_wizard_access.xml

...r-android/src/main/res/layout/fragment_mailbox_status.xml

briar-android/src/main/res/values/attrs.xml

briar-android/src/main/res/values/strings.xml