Clean up TypedArray docs & formatting, remove coercion warnings

Establishes a clear contract regarding when exceptions will be thrown,
when default values will be returned, and when values will be coerced
to a different type.

Since we have both getInt() and getInteger() where one handles coercion
without throwing an exception, it seems reasonable that we should clearly
document the behavior so that developers can make an informed decision.
Once we document the behavior, there is no reason to log warnings on
coercion. If a developer chooses to use a particular API or data type,
that is still correct according to the API.

BUG: 18625719
Change-Id: I385f0b719182d3c0358943e1d6c3d7bedc756eb5