Updates border color to have more contrast to the background, and adds
2dp padding between the border and the task content view - done by
updating BorderAnimator not to assume the border width and stroke are
the same.
Adding padding between the border and task view content exopsed an issue
where the second thumbnail in a split task's borders were not clipped
correctly when adding a border (it looked like the clip rect was not
properly scaled down). This is addressed by moving the tack view
background (and the outline) from the root KeyboardQuickSwitchTaskViews
to the content views (i.e. moving the outline to the view that does not
get scaled when adding a border, and having the second thumbnail end
edge of the clip rectangle match the clip rectangle of the clipped
ancestor view).
Bug: 398770098
Test: Manual
Flag: EXEMPT (a11y) bug fix
Change-Id: Ie058c932411a6b47815b0abf756f739c55b8342f
TLDR:
* This change should not break anything or change any color.
* Simplifies theming and styling while improving developer experience.
* With this developers can often skip styling for color entirely, while ensuring consistency and preventing accidental overrides.
Bug: 374273611
Test: presubmit
Flag: EXEMPT bugfix
Change-Id: Id19038078e83c73847b1a7c686c3a3df1ecccac2
