Limit the number of concurrently snoozed notifications

Test: atest FrameworksUiServicesTests
Bug: 234441463
Change-Id: I005b43979d1c708fd505c8b33ae0c8cb03ddbb35
(cherry picked from commit 7c38394ae9c69620499a87e629edae4fe0ac4edc)
4 files changed