Updates to default values

- all classification types are allowed by default
- Only reload nas unsupported defaults on nas change/upgrade

Test: NotificationAssistantServiceTest
Test: NotificationAsssistantsTest
Bug: 367996732
Bug: 388485761
Flag: android.app.nm_summarization
Change-Id: Ie649222d6dd059eb8712f2c623b9403113004ac0