I don't think I've ever heard of a bear breaking into a hard sided RV. They are smart so anything is possible. Back in the '70s the rangers in the Yosemite Valley were having a problem with bears breaking into cars. They had just switched to those trash containers with the mailbox style door in the top. They found one sow dropping her cubs down thru the door. But those bears are quite used to human presence.
Personally I probably wouldn't worry about it much unless I saw clear evidence that there was something to worry about it. Maybe keep the grill away from the camper but we have never scrubbed down the grill when we were in bear country.