[material_ui] SearchAnchor overlay expands to full screen when viewport size changes

[elliette]

Port over flutter/flutter#186537 from flutter/flutter.

Fixes flutter/flutter#186154

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[gemini-code-assist]

Code Review

This pull request wraps the SearchAnchor view content in a LayoutBuilder to dynamically adjust its constraints based on the parent container, enabling the full-screen view to resize on viewport changes such as device rotation. The review feedback suggests setting minWidth and minHeight to 0.0 when showFullScreenView is true to prevent potential overflow issues when parent constraints are smaller than the minimum dimensions.

[gemini-code-assist]

When widget.showFullScreenView is true, the search view is intended to be full screen. If the parent constraints are smaller than minWidth or minHeight (e.g., on very small screens or inside a small nested Navigator), forcing the constraints to minWidth/minHeight via math.max will cause the full-screen view to overflow its parent boundaries.

Instead of forcing the maximum constraints to be at least minWidth/minHeight, we can set the minWidth/minHeight to 0.0 when widget.showFullScreenView is true. This allows the full-screen view to scale down and fit perfectly within the parent constraints without overflowing or throwing assertion errors.

              constraints: BoxConstraints(
                minWidth: widget.showFullScreenView ? 0.0 : minWidth,
                maxWidth: widget.showFullScreenView
                    ? constraints.maxWidth
                    : _viewRect.width,
                minHeight: widget.showFullScreenView ? 0.0 : minHeight,
                maxHeight: widget.showFullScreenView
                    ? constraints.maxHeight
                    : _viewRect.height,
              ),