Facet with boolean type for property is not managed

[fredgaillardUniDistance]

Describe the issue
Facet with boolean type for property is not managed

To Reproduce
add
"mappings": {
"date_detection": false,
"numeric_detection": false,
"properties": {
"$schema": {
"type": "text",
"index": false
},
...
"is_fun": {
"type": "boolean"
},
...
Expected behavior
...
Trace
core.js:6210 ERROR Error: Parameter "key" required
at TranslateService.instant (ngx-translate-core.js:990)
at BucketsComponent.getBucketName (rero-ng-core.js:15893)
at BucketsComponent_ul_0_li_1_Template (rero-ng-core.js:2163)
at executeTemplate (core.js:9614)
...

Request url
http://localhost:4200/api/testresource/?q=&page=1&size=1&facets=is_fun

Network preview
{aggregations: {is_fun: {,…}},…}
aggregations: {is_fun: {,…}}
is_fun: {,…}
buckets: [{doc_count: 47, key: 0, key_as_string: "false"}, {doc_count: 11, key: 1, key_as_string: "true"}]
0: {doc_count: 47, key: 0, key_as_string: "false"}
1: {doc_count: 11, key: 1, key_as_string: "true"}
...