[FEATURE REQ] Improve FileContent.toStream().

[kasobol-msft]

Follow up from #29047 .

The FileContent.toStream() looks like this:

azure-sdk-for-java/sdk/core/azure-core/src/main/java/com/azure/core/implementation/util/FileContent.java

Lines 86 to 93 in 8d5049c

	@Override
	public InputStream toStream() {
	try {
	return new BufferedInputStream(new FileInputStream(file.toFile()), chunkSize);
	} catch (FileNotFoundException e) {
	throw LOGGER.logExceptionAsError(new UncheckedIOException("File not found " + file, e));
	}
	}

This has the following problems:

• Setting chunkSize large make BufferedInputStream allocate large arrays.
• The return stream's mark/reset would use BufferedInputStream imlementation that would buffer in memory up to readLimit.

These are inefficient given that file is a durable and seekable source.

We should consider building input stream based on filechannel instead. The built in Channels.newInputStream aren't great - they don't allow mark/reset, so we should probably go for custom implementation.

[github-actions]

Hi @kasobol-msft, we deeply appreciate your input into this project. Regrettably, this issue has remained unresolved for over 2 years and inactive for 30 days, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.