We had logic in flat_object parsing that would:

1. Try parsing a flat object field that is not an object or null.
2. Would see an END_ARRAY token, ignore it, and not advance the parser.

Combined, this would create a scenario where passing an array of
strings for a flat_object would parse the string values, then loop
infinitely on the END_ARRAY token.

Signed-off-by: Michael Froh <[email protected]>

The removed code does not actually seem to affect the logic. Also, I
want to be 100% sure that every call to parseToken is guaranteed to
call parser.nextToken() at some point.

Signed-off-by: Michael Froh <[email protected]>

Thanks for the reminder, @kkewwei!

Signed-off-by: Michael Froh <[email protected]>

The test fails on MixedClusterClientYamlTestSuiteIT because 2.x still
has the infinite loop until backport.

Signed-off-by: Michael Froh <[email protected]>