ClientTelemetryTests flaky

[j82w]

The trace even shows the CPU as NaN: DocDBTrace Information: 0 : System Usage recorded by telemetry is : {"systemHistory":[{"dateUtc":"2021-09-13T15:25:24.0897374Z","cpu":NaN,"memory":11566524.000,"threadInfo":{"isThreadStarving":"False","threadWaitIntervalInMs":0.6365,"availableThreads":32764,"minThreads":8,"maxThreads":32767}}]}

This causes the following assert to fail.
Assert.AreEqual failed. Expected:<2>. Actual:<1>. System Information Count doesn't Match; [{"metricInfo":{"metricsName":"MemoryRemaining","unitName":"MB","mean":10821.59375,"count":1,"min":10822.0,"max":10822.0,"percentiles":{"50":10821.6240234375,"90":10821.6240234375,"95":10821.6240234375,"99":10821.6240234375,"99.9":10821.6240234375}}}]

[sourabh1007]

It will return CPU usage as NaN only in following cases:

• If Native Function (Windows : kernel32.dll, Linux: /proc/stat) is not returning any value.
• If totalElapsedTime is zero means difference between 2 consecutive reading are zero.

Related PR is out to fix this isue

[sourabh1007]

Fix will be available in the latest Direct package.

[j82w]

Please keep this issue open until the direct package is updated and the assert is re-enabled in the test. Without an issue to track it the assert will not get enabled again.