Use interfaces for Polly retry policies in C#

[jacobilsoe]

This enables use of Polly.ResiliencePipelineBuilder where the built Polly.ResiliencePipeline returns an interface when using properties AsSyncPolicy or AsAsyncPolicy.

@mandrean @shibayan @Blackclaws @lucamazzanti @iBicha

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[wing328]

@jacobilsoe thanks for the PR

is this change backward compatible?

[jacobilsoe]

@jacobilsoe thanks for the PR

is this change backward compatible?

@wing328 Well, that depends on what you mean by backwards compatible. 😃

Policy/AsyncPolicy implements ISyncPolicy/IAsyncPolicy so in that way the change is backwards compatible.

But if someone uses members of e.g. the Policy class that are not in the ISyncPolicy interface they will get a compile error.

However, the intention of the RetryPolicy/AsyncRetryPolicy properties is for users to set them, not get them. Right?

[wing328]

thanks for the details and pointing out edge cases in which this may break users applications using the C# SDKs.

i would go ahead with this change and if someone needs a way to rollback, we will consider providing one.

[wing328]

thank for the PR, which has been merged.

have a good week ahead.