Tie Android Browser version to Android OS version

[TomMettam]

Firstly, I propose that Browser::NAVIGATOR be changed to Browser::ANDROID - the official name of the app is "Android Browser", Navigator doesn't appear.

The detection of the Version/4.0 string is supposed to be correct, but the fact is that /every/ version of the Android Browser reports as Version/4.0.

Since the Android Browser is a core part of the Android OS, I propose that the OS version be used.

Some info to back up my proposal:

Mozilla/5.0 (Linux; U; Android 4.2.2; de-de; SM-T110 Build/JDQ39) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Safari/534.30

Here the Android browser is using WebKit

Mozilla/5.0 (Linux; Android 4.4.4; SM-G360H Build/KTU84P) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/33.0.0.0 Mobile Safari/537.36

Here the Android browser is using Blink

The layout engine was upgraded to Blink with the release of Android 4.4, which makes it almost an entirely new browser, but yet both are reported as Version/4.0.