Update connectivity diagnostics manifest

BUG=336873

Review URL: https://codereview.chromium.org/131103013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246488 0039d316-1c4b-4281-b951-d872f2087c98
Export oobe_exists to cros_browser_with_oobe.

Rename OobeExists/_OobeExists to property oobe_exists.

BUG=336888
TEST=manual
NOTRY=True

Review URL: https://codereview.chromium.org/144183008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246489 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246488
SVN changes up to revision 246489