For #6968 Close response stream to allow use of caching

app/src/main/java/org/mozilla/fenix/settings/search/SearchStringValidator.kt

@@ -21,6 +21,9 @@ object SearchStringValidator {
         } catch (e: IOException) {
             return Result.CannotReach
         }
+
+        // read the response stream to ensure the body is closed correctly. workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=1603114
+        response.body.string()
         return if (response.isSuccess) Result.Success else Result.CannotReach
     }