BrowserSettings: update desktop UA string to match Chrome 33

This matches the corresponding update to Chromium 33 for Android WebView.

Change-Id: Id2a8a832c2a637f7c5284d5006b6f3475bfba560
Merge branch 'cm-11.0' of github.com:CyanogenMod/android_packages_apps_Browser into kk4.4