DO NOT MERGE: Remove StuckServer using backlog and tests relying on it

This cherry-pick contains additional changes to remove more references
to StuckServer. The URLConnectionTest#teestConnectTimeouts() test is
suppressed in M via libcore/expectations/brokentests.txt and is not
expected to work. This change should not be merged into N branches.
(Original commit description follows below.)

StuckServer uses kernel implementation details that have changed on
version > 4.4, and causing tests depending on it to fail. Since we can't
find an alternative method to simulate a stuck server without special
permission, and the test itself is not reliable in that they don't fail
on non-stuck servers, remove them from Libcore tests.

Test: CtsLibcoreTestCases
Test: rm -rf out; m -j30 cts
Bug: 32551747
Bug: 35934294
(cherry picked from commit b5c7cd37)

Change-Id: I4dd951e9527b5ee5701c0c3ad3eaa0c6f34e8ef7