Improve IDisposable inheritance examples

[MSDN-WhiteKnight]

Update IDisposable inheritance examples to use FileStream instead of IntPtr.Zero safe handle. Using IntPtr.Zero handle is invalid and causes issues in Linux, where zero handle refers to stdin stream. There are some unrelated changes in VB, they are needed to make project compile, because there were name collisions.

Related to: dotnet/runtime#64305

[opbld32]

Docs Build status updates of commit 490ac6f:

✅ Validation status: passed

File	Status	Preview URL	Details
snippets/csharp/System/IDisposable/Overview/base1.cs	✅Succeeded	View
snippets/csharp/System/IDisposable/Overview/derived1.cs	✅Succeeded	View
snippets/fsharp/System/IDisposable/Overview/base1.fs	✅Succeeded	View
snippets/fsharp/System/IDisposable/Overview/derived1.fs	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/IDisposableSnippets.vbproj	✅Succeeded
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/base1.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/calling2.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/derived1.vb	✅Succeeded	View

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[opbld34]

Docs Build status updates of commit 67e6cca:

✅ Validation status: passed

File	Status	Preview URL	Details
snippets/csharp/System/IDisposable/Overview/base1.cs	✅Succeeded	View
snippets/csharp/System/IDisposable/Overview/derived1.cs	✅Succeeded	View
snippets/fsharp/System/IDisposable/Overview/base1.fs	✅Succeeded	View
snippets/fsharp/System/IDisposable/Overview/derived1.fs	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/IDisposableSnippets.vbproj	✅Succeeded
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/base1.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/calling2.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/derived1.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/derived2.vb	✅Succeeded

For more details, please refer to the build report.

Note: Broken links written as relative paths are included in the above build report. For broken links written as absolute paths or external URLs, see the broken link report.

For any questions, please:

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• Post your question in the Docs support channel

[opbld34]

Docs Build status updates of commit 67e6cca:

✅ Validation status: passed

File	Status	Preview URL	Details
snippets/csharp/System/IDisposable/Overview/base1.cs	✅Succeeded	View
snippets/csharp/System/IDisposable/Overview/derived1.cs	✅Succeeded	View
snippets/fsharp/System/IDisposable/Overview/base1.fs	✅Succeeded	View
snippets/fsharp/System/IDisposable/Overview/derived1.fs	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/IDisposableSnippets.vbproj	✅Succeeded
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/base1.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/calling2.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/derived1.vb	✅Succeeded	View
snippets/visualbasic/VS_Snippets_CLR_System/system.idisposable/vb/derived2.vb	✅Succeeded

For more details, please refer to the build report.

Note: Broken links written as relative paths are included in the above build report. For broken links written as absolute paths or external URLs, see the broken link report.

For any questions, please:

• Try searching the docs.microsoft.com contributor guides
• Post your question in the Docs support channel

[BillWagner]

Thanks @MSDN-WhiteKnight This is great, and I'll now.