Bug 984274 - Disable test_sandbox_permission.html on B2G for too many intermittent failures

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extra : rebase_source : 1774eb1f371100ab13d1711855776d4d708395fd
Bug 1023341 - Disable test_networkstats_alarms.html on B2G for too many intermittent test failures

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extra : rebase_source : 11cc5584e6bb765587ca988531c8f131055c08d5