Add page for choosing calendar & reply for event modes.

Also adds the link to set trigger behavior to the main mode page (only for calendar so far), and the switch preference to enable/disable automatic rules (for all but manual DND mode).

Removes the "escape hatch" to allow manual mode to also use the new modes pages.

Ported from ZenModeEventRuleSettings.

Flag: android.app.modes_ui
Bug: 332730302
Test: ZenModeSetCalendarPreferenceControllerTest, ZenModeSetTriggerLinkPreferenceControllerTest, manual
Change-Id: Ia7a716c66663a21494a6c05711250a5bda87ca8c