Remove support for CombinedVibration.SequentialCombination

This API for combining a sequence of synchronized vibration effects was
never released and is not well supported.

Removing the unused framework code to support this unreleased fearure.

Bug: 421857859
Flag: android.os.vibrator.remove_sequential_combination
Test: FrameworksVibratorServicesTests
Change-Id: I71882414032d52532fe9fd835932cec133d4adfb