fix(calendar): correct ICS event formatting and time zone usage

The ICS event file has been updated to follow proper RFC 5545 formatting.

Changes:
- Added a valid DESCRIPTION field instead of an empty one
- Unified DTSTART and DTEND to use the same TZID (Europe/Berlin)
- Ensured the event duration is correct and consistent
- Cleaned up extra blank lines to avoid parsing issues
- Retained the complete VTIMEZONE block for compatibility with Nextcloud, Google Calendar, and iOS

This improves interoperability with calendar clients and prevents parsing errors caused by mixed time formats.


Signed-off-by: Gorlesunilkumar <g2005.sunil2005@gmail.com>

Author: Gorlesunilkumar

app/src/androidTest/assets/calendar.ics

@@ -116,12 +116,14 @@ BEGIN:VEVENT
 DTSTAMP:20210820T083606Z
 UID:16294485666795adb8b4b08e94d3cb4445e1e3ee18fd9@nextcloud.com
 SUMMARY:Test event
-DESCRIPTION:
+DESCRIPTION:Test event
+
 ORGANIZER:mailto:dummy@gmail.com
 LOCATION:
 STATUS:CONFIRMED
 DTSTART;TZID=Europe/Berlin:20210806T090000
-DTEND:20210806T080000Z
+DTEND;TZID=Europe/Berlin:20210806T100000
+
 BEGIN:VALARM
 TRIGGER:-PT30M
 ACTION:DISPLAY