I have no better idea for osmand than ....
to use over pass
https://overpass-turbo.euYou can query for your area
/*
This has been generated by the overpass-turbo wizard.
The original search was:
“"fire hydrant"”
*/
[out:json][timeout:25];
// gather results
(
// query part for: “"fire hydrant"”
node["emergency"="fire_hydrant"]({{bbox}});
);
// print results
out body;
>;
out skel qt;
Results can be saved as gpx. This gpx can be imported in osmand then you can set any desc and icon manually one by one.
tedious/time consuming but no any other idea, sorry