update targetSdkVersion to 34

[antest1]

will apply after 2025 event ends (late spring?) don't want to risk during the event
since lots of dependency updates requires sdk 34+ so would be better to work on this year

Checklist

• SCHEDULE_EXACT_ALARM denied by default (currently asks to grant permission before starting service)
• add foreground service type (will use FOREGROUND_SERVICE_SPECIAL_USE)
• OpenJDK 17 (changed from 3.0 rev2)
• check implicit/pending intents behaviors
• specify export behavior for runtime-registered broadcast receivers (done in 3.0 rev2)
• check restriction on starting activities from the background