Allow apps to set vibrations pattern for channels

Test: runtest systemui-notification, cts
Change-Id: I9125e9c437e3888ba7e7582bb3557635a2aea893

• api/current.txt[diff]
• api/system-current.txt[diff]
• api/test-current.txt[diff]
• core/java/android/app/NotificationChannel.java[diff]
• services/core/java/com/android/server/notification/NotificationRecord.java[diff]
• services/core/java/com/android/server/notification/RankingHelper.java[diff]
• services/tests/notification/src/com/android/server/notification/BuzzBeepBlinkTest.java[diff]
• services/tests/notification/src/com/android/server/notification/NotificationRecordTest.java[diff]
• services/tests/notification/src/com/android/server/notification/RankingHelperTest.java[diff]