Make JSONObject summary documentation clearer.

The class documentation makes the difference between the 'get' and 'opt'
methods very clear, but it's less clear to anyone just looking at the
summary of methods.

Bug: https://code.google.com/p/android/issues/detail?id=60998
Change-Id: I17eeaea182a9dbad7be9fbd55086977b512b6fa8
1 file changed