Fix missing bubble update dot

Don't update the dot scale if the bubble bar is not collapsing or
expanding.

Flag: com.android.wm.shell.enable_bubble_bar
Bug: 351904597
Test: manual
       - Create 2 bubbles in the bubble bar
       - Select both bubbles to clear the dot
       - Launch an app to stash the bar
       - Send updates to both bubbles
       - Observe dot appears during each animation
       - Swipe up on the bubble bar
       - Observe dot disappears for the selected bubble but remains
         for the unselected bubble
Change-Id: I2cb6dd7ded261686ae73e497bd5d4841ebde35ef