Re-enable WaitForInitialUserActivitySatisfied.
Re-enable WaitForInitialUserActivitySatisfied.

Ran 50 times without fail.

BUG=315308

Review URL: https://codereview.chromium.org/1410163002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#356974}

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