Gallery: Prevent display "Show on map" menu if no geo view is present

Change-Id: I8520bd227295eaa77fd8d63dbd9b5758dbd7bf01
JIRA: CYAN-2005
Issue: https://jira.cyanogenmod.org/browse/CYAN-2005
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>