Create BubbleTaskViewHelper to be shared with new bubble expanded view

For the bubble bar we will create a different expanded view to show
the bubble in. This change factors out common code so that it can
be shared between the two separate views.

Currently not used by BubbleExpandedView but will be later.

Test: atest BubblesTests
Bug: 253318833
Bug: 272102927
Change-Id: I8beec37e33fd3e10d9bd603b681b845785c64534