[bp/1.25] test: fix flaky test DownstreamProtocolIntegrationTest.HandleDownstreamSocketFail (#27546)

[phlax]

The test manually introduces EBADF error on the connection between Envoy and the test client. However, the IoHandleMatcher doesn't distinguish UDP socket from TCP. If the upstream HTTP/3 connection gets the same port number as downstream TCP connection, the EBADF error will be applied to the wrong connection.

Enforce IoHandleMatcher to match socket type.

Risk Level: low, test only
Testing: existing tests
Docs Changes: N/A
Release Notes: N/A
Partially Fix #27490

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[phlax]

this is failing with

test/integration/shadow_policy_integration_test.cc:18:9: error: member initializer 'SocketInterfaceSwap' does not name a non-static data member or base class
        SocketInterfaceSwap(Network::Socket::Type::Stream) {
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

i guess if we want to pick this to this branch we will need to pick other change/s also

[danzh2010]

this is failing with

test/integration/shadow_policy_integration_test.cc:18:9: error: member initializer 'SocketInterfaceSwap' does not name a non-static data member or base class
        SocketInterfaceSwap(Network::Socket::Type::Stream) {
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

i guess if we want to pick this to this branch we will need to pick other change/s also

What this branch is? The PR just fixed a test utility. Why is it need to be picked into a specific branch?

[phlax]

thanks @danzh2010 for clarification offline - seems this should not be necessary