Switch SSLClientSocketReadTest.Read_WithFatalAlert to EmbeddedTestServer

BoringSSL has an API we can call to send a fatal alert.

Bug: 1250903
Change-Id: I03f8314588216dfb5941bf26f2101f2aacc5c395
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3283144
Commit-Queue: David Benjamin <davidben@chromium.org>
Reviewed-by: Matt Mueller <mattm@chromium.org>
Cr-Commit-Position: refs/heads/main@{#942320}
NOKEYCHECK=True
GitOrigin-RevId: 50c88f97667a68d84c6a18689a5dd04319aeec9c