Calendar Notifications NG

Fork of my original "Calendar Notifications Plus" app, this app is a test-site for the new features.

This app would replace calendar event notifications, providing snooze functionality and notifications persistence.

For this app to work it must be opened at least once after installation. Please don't forget to grant required calendar access permissions.

IMPORTANT: please disable any Android power optimizations for this app (it won't consume much power), it is required for reliable operation:

* Samsung users: power saving for this app should be disabled in two places: 1) Android Settings -> Battery -> App Power Saver -> Details; 2) Android Settings -> Battery -> Battery Usage -> More -> Optimize Battery Usage.

* Xiaomi/MIUI users: to disable power saving for this app, open Security app, go to Battery -> App battery saver and change background settings for this app to "No restrictions"

* Instructions for other devices would be added later