Add XML documentation to Android.Graphics.Color static component-accessor methods

[Copilot]

The four static component-accessor methods on Android.Graphics.Color (GetAlphaComponent, GetRedComponent, GetGreenComponent, GetBlueComponent) lacked XML documentation, leaving IntelliSense without any hint about the expected color argument or the 0–255 return range. These are the static counterparts to the A/R/G/B instance properties documented in #11581.

Changes

• Added <summary>, <param>, and <returns> doc comments to all four static accessor methods in src/Mono.Android/Android.Graphics/Color.cs.
• <see cref="ToArgb"/> references resolve to the existing instance method, avoiding CS1574 warnings.
• No method bodies changed; #region/#endregion markers preserved.

/// <summary>
/// Extracts the alpha (opacity) component from a packed ARGB color integer, where 0 is fully transparent and 255 is fully opaque.
/// </summary>
/// <param name="color">A packed ARGB color integer, such as the value returned by <see cref="ToArgb"/>.</param>
/// <returns>The alpha component of <paramref name="color"/>, in the range 0–255.</returns>
public static int GetAlphaComponent (int color)
{
	return (byte)(color >> 24);
}

[Copilot]

Pull request overview

Adds missing XML documentation for Android.Graphics.Color’s static ARGB component accessor methods so IntelliSense describes the expected packed int input and the 0–255 component return range, aligning these APIs with the already-documented instance component access patterns.

Changes:

• Added <summary>, <param>, and <returns> XML doc comments to GetAlphaComponent, GetRedComponent, GetGreenComponent, and GetBlueComponent.
• Referenced <see cref="ToArgb"/> as an example source for the packed ARGB integer.
• No behavioral/code changes to the methods themselves.