linux embeded unit tests flaky on TestPlatformTime.cpp:116

[woody-apple]

@turon The test failure is:

Failed assert: Tdelta < (Tdelay + margin) in ../../../../../src/platform/tests/TestPlatformTime.cpp:116

That doesn't seem related to these changes. Is that test known to intermittently fail?

Originally posted by @bzbarsky-apple in #857 (comment)

[woody-apple]

@turon could you take a look? Spinning again worked...

[turon]

@woody-apple Yes the time tests check that delays of a certain value land in a threshold window. The margin is clearly too tight for the CircleCI environment. I can relax the margins as a first pass. Worst case, we can disable those tests.

[turon]

FYI, the test margins are currently here:
https://github.com/project-chip/connectedhomeip/blob/master/src/platform/tests/TestPlatformTime.cpp#L31

#define TEST_TIME_MARGIN_MS 2
#define TEST_TIME_MARGIN_US 500

[woody-apple]

Can we up those margins for CI?