Use ParceledListSlice for ZenModeConfig and AutomaticZenRules

Also, use writeString8 for Zen-related parceling.

Bug: 387498139
Test: atest NotificationManagerZenTest ZenModeConfigTest
Flag: EXEMPT Serialization change with good test coverage
(cherry picked from commit 3965123f)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:067a8e500c707ab94d2268f9f4c84f9443143e98)
Merged-In: I9925c9bcc542781832d111660e22181151526127
Change-Id: I9925c9bcc542781832d111660e22181151526127