fix: handle Chrome location on Windows

Currently the task assumes Chrome is located under process.env.LOCALAPPDATA
directory. This may not be as Chrome can be installed globally, to
process.env["PROGRAMFILES(X86)"]. Should Chrome be released for Windows in a 64-bit
flavor, it can be located under process.env.PROGRAMFILES. This commit adds fallbacks
to those paths, being forward-compatible in case 64-bit Chrome gets released for Windows.

Analogous PR for Firefox: https://github.com/karma-runner/karma-firefox-launcher/pull/9