[Android] Add repeat argument to UiRobot tests.
[Android] Add repeat argument to UiRobot tests.

The test runner assumes that all tests ran in platform
mode of the args.repeat attribute. This is causing the
UiRobot tests to crash since they don't have this.

BUG=

Review URL: https://codereview.chromium.org/1415753002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#354901}

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