Don't remove the bubble if there's a later update

When the removal event is received from launcher, we now check the
removal timestamp against the most recent update before removing it.

This helps ensure that we don't remove bubbles when there are unseen
updates.

Flag: com.android.wm.shell.enable_bubble_bar
Bug: 351026092
Test: atest BubbleDataTest
Change-Id: Ib59658b6dcebc1da0281239be4621250289f7158