Call launchGetThemesWebView if ActivityNotFound.

Themes Showcase may be installed but disabled by the user.  If this
is the case an ActivityNotFoundException will be thrown.  We catch
this exception and show the themes web view instead.

Change-Id: I5771215b27493bbfa8fa2643cd1e7c3ec2986ded
Hardcode 'Get More' entries

Previously entries were populated from the wiki causing:
(1) Language support to not work because the server does not respect accepted-languages header
(2) The wiki caches articles and can cause changes to not be updated quickly enough.

So until this is fixed we will stick with hardcoded entries in the strings.xml

Change-Id: I852da3b8dad91665f4cdeda450ff9158369cb55a
ThemeChooser: fix theme apps link

Change-Id: Ia83f764eeac72c6dac6346c156f6d0ef03d33379