ContentValues: improve documentation

Correct and clarify the documentation for ContentValues.

Signed-off-by: Steve Pomeroy <steve@staticfree.info>

(cherry picked from commit 1276b5f29ed6f889e9691cf296fd9911958895c1)

Change-Id: Id6f4e93dcca64dd41daeb4066d804ff173f4747b
1 file changed