A pair of fixes for native anroid browser

The native android browser doesn't allow us to `preventDefault` in the `touchend` event. Thus, we need to `preventDefault` in the `click` handler which is done for `vjs.Button`. The `MediaTechController` is just made to not toggle the play state if on the android browser by making `onClick` a no-op on the native android browser.
Detection for the native android browser is currently done by looking for `android` and making sure that `chrome` isn't in the `userAgent`.