[HybridClockTest] update TestNtpDiagnostics scenario

This changelist updates HybridClockTest.TestNtpDiagnostics scenario
to work even if the NTP diagnostic tools are absent.  The idea is
to verify that appropriate tools are run or attempted to run, and
that's already enough.

The motivation for this changelist was the absence of 'ntptime', 'ntpq',
and other NTP-related tools in macOS Catalina and newer.  As for the
deprecation of 'ntpd' on macOS, it's replaced with 'timed' [1] starting
macOS HighSierra (10.13).  The 'ntpd' and legacy NTP tools are still
there in macOS HighSierra, but 'ntpd' is longer running ('timed' is used
instead).  It seems starting with Catalina they removed 'ntpd' and the
legacy NTP tools such as 'ntptime', 'ntpq', 'ntpdc', etc.

[1] https://forums.developer.apple.com/thread/83240

Change-Id: I6fb3467ce289eaaf394add0a72fbf5022a96fd70
Reviewed-on: http://gerrit.cloudera.org:8080/15774
Reviewed-by: Volodymyr Verovkin <verjovkin@cloudera.com>
Reviewed-by: Grant Henke <granthenke@apache.org>
Tested-by: Alexey Serbin <aserbin@cloudera.com>
1 file changed