Rename android_build_type to android_webview_build.

Rename android_build_type to android_webview_build.

Rename this gyp variable to something meaningful to better explain what
it actually does.

BUG=184431
Committed: https://code.google.com/p/v8/source/detail?r=13916

[Torne, 2013-03-12 11:23:46]

This is a followup to Chromium r187556 which renamed this variable (the old name
is still defined as well for now).

[mnaganov (inactive), 2013-03-12 11:51:40]

Hi Yang,

Can you please take a look at this change? This is after a cleanup done here:
http://src.chromium.org/viewvc/chrome?view=rev&revision=187556

[Yang, 2013-03-12 12:10:53]

On 2013/03/12 11:51:40, Mikhail Naganov (Chromium) wrote:
> Hi Yang,
> 
> Can you please take a look at this change? This is after a cleanup done here:
> http://src.chromium.org/viewvc/chrome?view=rev&revision=187556

LGTM. Drop me a line if you want me to commit it.

[mnaganov (inactive), 2013-03-12 13:07:19]

On 2013/03/12 12:10:53, Yang wrote:
> On 2013/03/12 11:51:40, Mikhail Naganov (Chromium) wrote:
> > Hi Yang,
> > 
> > Can you please take a look at this change? This is after a cleanup done
here:
> > http://src.chromium.org/viewvc/chrome?view=rev&revision=187556
> 
> LGTM. Drop me a line if you want me to commit it.

Thanks! If you have time, please do.

[Yang, 2013-03-12 17:35:38]

Committed patchset #1 manually as r13916 (presubmit successful).