docs: update homepage I/O announcement

alt="Android at Google IO 2011" width="200px"

alt="Android at Google IO 2011" width="200px"

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    <p>Google I/O is a two-day developer event that will take place May 10-11 at Moscone Center, San

    <p>Thanks to everybody who joined us at Google I/O! If you couldn't make it or would like to

Francisco. The agenda includes several sessions about Android, presented by Android engineers and

review any of the Android sessions, they're now available on YouTube at the <a

other team members.</p><p><a href="http://www.google.com/events/io/2011/sessions.html">Learn

href="http://www.youtube.com/googledevelopers">Google Developers</a> channel, along with the keynote

more &raquo;</a></p>

and other developer sessions. You can also find all the Google I/O Android sessions on this site, on

the <a href="{@docRoot}videos/index.html">Videos</a> page.</p>

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