refactor(Android, FormSheet v5): Separate layout management for FormSheet

[t0maboro]

Description

Following the extraction of the lifecycle coordinator, this PR further refactors the FormSheetDialogManager. All logic related to view dimensions and insets has been decoupled into dedicated coordinator.

Changes

• Moved all insets handling, dynamic container height calculations, and dimension states into a dedicated coordinator. The main manager now only delegates the resolved detents to this class when the configuration changes.
• Moved the translationY = height pre-draw setup to FormSheetAnimationCoordinator.prepareViewForAnimation - preparing the initial state of an animation is now explicitly handled on the animation layer.
• disableMaterialInsetsAnimationCallback now is rewired to OnLayoutChangeListener, rather than relying on the OnPreDrawListener, which would run after calculating the layout, but the newly registered callback is more explicit regarding the intention.

Before & after - visual documentation

N/A - refactor

Test plan

Already existing SFTs.

Checklist

• Included code example that can be used to test this change.
• For visual changes, included screenshots / GIFs / recordings documenting the change.
• For API changes, updated relevant public types.
• Ensured that CI passes

[Copilot]

Pull request overview

Refactors the Android FormSheet implementation by extracting view sizing/insets responsibilities out of FormSheetDialogManager into a dedicated coordinator, and clarifies animation setup responsibilities inside the animation layer.

Changes:

• Introduces FormSheetDimensionsCoordinator to own window-insets handling, container height stabilization, and detent-driven sizing/behavior updates.
• Moves the “initial offscreen position” setup (translationY = height) into FormSheetAnimationCoordinator.prepareViewForAnimation.
• Rewires the Material insets-animation callback disabling to a layout-driven hook (instead of pre-draw) via the new coordinator.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
android/src/main/java/com/swmansion/rnscreens/gamma/modals/formsheet/FormSheetDimensionsCoordinator.kt	New coordinator that centralizes insets + stable container height updates and detent application.
android/src/main/java/com/swmansion/rnscreens/gamma/modals/formsheet/FormSheetDialogManager.kt	Simplifies manager to delegate dimension/behavior concerns to the coordinator and animation prep to the animation coordinator.
android/src/main/java/com/swmansion/rnscreens/gamma/modals/formsheet/FormSheetAnimationCoordinator.kt	Adds prepareViewForAnimation to explicitly manage initial animation state setup.

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