Enable Built-in COM interop for ContentIsland sample

[Zakariathr22]

Description

Explicitly enables built-in COM interop in the project by setting true in the .csproj file.
This ensures that the ContentIsland sample can load models without throwing a System.NotSupportedException when trimming is enabled.

Motivation and Context

• Fixes Built-in COM disabled via feature switch when loading ContentIsland sample #2074

How Has This Been Tested?

Tested by running the ContentIsland sample locally in both Release and Debug mode.

Screenshots (if appropriate):

None

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

[Zakariathr22]

Important

I’m not sure if this will impact the NAOT adoption in PR #2095, so it may need verification to ensure there are no runtime issues.