fix(launcher): send sigkill on timeout when force killing

[bkakadiya42]

@dignifiedquire This is in response to bug we are seeing where karma hangs because it is unable to force kill chrome, possibly #24 (comment)

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[bkakadiya42]

I signed it!

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CLAs look good, thanks!

[dignifiedquire]

Thanks, can you change the commit message to befix(launcher: instead of bug please?

[bkakadiya42]

@dignifiedquire, i updated the commit message, thanks.

[avaer]

@dignifiedquire Any ETA/version for this PR landing?