Override getClipBounds to expose overflow clipping to the framework

[fabriziocucci]

Summary:
Override getClipBounds() on ReactViewGroup to return the padding box rect when
overflow is hidden or scroll, gated behind the syncAndroidClipBoundsWithOverflow
feature flag.

This exposes the view's clipping behavior to the Android framework via the standard
View.getClipBounds() API:

• getClipBounds(Rect): Boolean returns true and populates the rect with the
  padding box when overflow is hidden/scroll, or false when overflow is visible
• getClipBounds(): Rect? returns the padding box rect or null respectively

This allows framework-level systems to inspect a view and determine whether it clips
its children by checking getClipBounds() != null, and to obtain the actual clipping
region for getGlobalVisibleRect() calculations.

Why not setClipBounds()?

An alternative approach would be to call View.setClipBounds(Rect) which sets the
mClipBounds field directly. This has the advantage of being picked up by AOSP's
ViewGroup.getChildVisibleRect() (which reads mClipBounds via direct field access
rather than calling getClipBounds()). However, setClipBounds() also propagates
the clip rect to the RenderNode via mRenderNode.setClipRect(), which clips the
view's own rendering — including its borders. It also requires maintaining a Rect
that must be kept in sync across size changes, border width changes, and overflow
changes.

For now, the getClipBounds() override is sufficient because harvesting systems
query the method rather than the field. If we find that AOSP's field-based path is
also needed, we can switch to setClipBounds() in the future.

Adds BackgroundStyleApplicator.getPaddingBoxRect() (internal via buck friend_paths)
which computes the padding box (view bounds minus border insets) reusing the same
border inset resolution logic as clipToPaddingBox().

Changelog: [Internal]

Reviewed By: twasilczyk, javache

Differential Revision: D102353840

[meta-codesync]

@fabriziocucci has exported this pull request. If you are a Meta employee, you can view the originating Diff in D102353840.

[meta-codesync]

This pull request has been merged in 2c208f8.