Add mayLaunchUrl and warmup methods in Android

[giannismacheras]

This would significantly improve performance.

[jdnichollsc]

Any pull request is welcome, thanks for report this issue mate! 👍

[vincent-paing]

Connect to the Custom Tabs service on the onStart() method of the Activities you plan to launch a Custom Tab from.

@jdnichollsc This might require a rewrite of the logic itself. Since the CustomTabsService has to be binded to the calling activity, It wouldn't make sense to do this in ChromeTabsManagerActivity since it gets recreated every time. It has to warmed up in the activity that has user interaction to open custom tabs, i.e, current activity from reactContext. I think we can hook into react lifecycle listeners. Is there a particular reason you felt the need for separate activity?