GEODE-5704: use untilAsserted to avoid early failure

[nonbinaryprogrammer]

There was an awaitility that intended to loop until data was consistent
but instead failed on the first pass if any keys weren't consistent.

Signed-off-by: khowe@pivotal.io

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[nonbinaryprogrammer]

Requesting review from @dhemery @mhansonp

[galen-pivotal]

You shouldn't need to catch and rethrow, as ThrowingRunnable throws Throwable. I think Awaitility will print the stack trace, too.