Add validation ai_addrlen in PosixSocketResolveTest

[MSoliankoLuxoft]

Enhanced the SunnyDay test in PosixSocketResolveTest to include checks for the ai_addrlen field. The test now verifies that ai_addrlen matches the expected size for sockaddr_in (IPv4) and sockaddr_in6 (IPv6) based on the ai_family value. This ensures that getaddrinfo correctly sets the length of the returned socket address structures.

b/349469318

[MSoliankoLuxoft]

According to the CI, some tests randomly fail even though they are not related to the commit itself. For example, in one CI build, the following test failed:
linux / linux-gcc-6-3 / gcc-6-3_3_test (pull_request) Failing after 5m.
This test was not even related to the committed changes. After re-triggering the CI build, the same test passed successfully:
linux / linux-gcc-6-3 / gcc-6-3_3_test (pull_request) Successful in 6m.
However, another test started to fail:
evergreen / evergreen-x64 / x64_2_test (pull_request) Failing after 10m,
but the test directly related to the commit passed without any issues:

2024-09-09T15:08:35.1359317Z [----------] 7 tests from PosixSocketResolveTest
2024-09-09T15:08:35.1359728Z [ RUN      ] PosixSocketResolveTest.SunnyDay
2024-09-09T15:08:35.1762355Z [       OK ] PosixSocketResolveTest.SunnyDay (40 ms)