[System.ServiceModel] Fixed Bug652331_2 test that failed on Jenkins by increasing timeout

Looks like the test takes quite a while so 10 seconds was just too short. Increasing the timeout to 20s seems to fix it.
Merge pull request #1387 from akoeplinger/improve-bug652331_2

[System.ServiceModel] Fixed Bug652331_2 test that failed on Jenkins by increasing timeout
[linker] blacklist System.Net.Sockets.MulticastOption fields

 - merge fix for https://bugzilla.xamarin.com/show_bug.cgi?id=21578
   the MulticastOption's 'private IPAddress local' field was
   removed by linker and the app crashed later at runtime.
 - when System.Net.Sockets.MulticastOption object
   is passed to System.Net.Sockets.Socket.SetSocketOption
   and thru it to System.Net.Sockets.Socket.SetSocketOption_internal
   it accesses passed object fields
   (thru few more native calls).
TZ display name changes no longer reset adjustment rules.
Reset of adjustment rules is mandatory when the base offset is changed because the rules are relative to the base offset.
Adjustment rules are now kept until the base offset changes.
Changed script DateTime.Now_Test.sh to use the compiled csharp.exe.
Revert "Disable building the NET 2.0 profile by default."

This reverts commit fe265502cc517e8374ce2988f31e88d4f3554d8a.

Revert this for now as it breaks too much stuff.
Install Mono.Cecil in the net 4.5 profile.
[runtime] Use a separate signal with the SA_RESTART flag set for suspending/resuming threads during debugging on android, since lots of android native code cannot handle the interruptions caused by the normal abort signal. Fixes #22968/#23987.
[xml] XmlElement.InnserXml seems to preserve whitespaces.

Fix for mdoc test regression (see commit comments on #661430f).