Allow certain response headers coming from AzurePipelinesCredential to be logged

[ahsonkhan]

These two response headers are useful for the service team to debug and diagnose issues, and hence it is requested that we do log them.

• x-vss-e2eid
• activityid

Given our logged headers are based on an allow list, currently these two headers are REDACTED.

azure-sdk-for-net/sdk/core/Azure.Core/src/DiagnosticsOptions.cs

Lines 44 to 71 in a70122e

	LoggedHeaderNames = new List<string>()
	{
	"x-ms-request-id",
	"x-ms-client-request-id",
	"x-ms-return-client-request-id",
	"traceparent",
	"MS-CV",
	"Accept",
	"Cache-Control",
	"Connection",
	"Content-Length",
	"Content-Type",
	"Date",
	"ETag",
	"Expires",
	"If-Match",
	"If-Modified-Since",
	"If-None-Match",
	"If-Unmodified-Since",
	"Last-Modified",
	"Pragma",
	"Request-Id",
	"Retry-After",
	"Server",
	"Transfer-Encoding",
	"User-Agent",
	"WWW-Authenticate" // OAuth Challenge header.
	};