Why:
- An empty array is a valid return value for the method, and...
- Without this, tests that use `executeHandler()` with an empty
parameters array (for example, the REST endpoint has no query
parameters) and items in the body params array will result in a
`getValidatedParams() called before validate()` exception in
`getValidatedParams`, because the Handler's `validatedParams` property
will be null instead of an empty array
What:
- Remove the truthiness check for query and body params, and always set
the array (empty or otherwise) as the return value for
`validateParams` and `validateBody`
Change-Id: I9cf36775b7392734b184b63023beef4a2a8434ac
774ba90fbb