Pass users followed tags to endpoint

WordPress/src/main/java/org/wordpress/android/ui/reader/services/discover/ReaderDiscoverLogic.kt

@@ -90,11 +90,13 @@ class ReaderDiscoverLogic @Inject constructor(
             params["tag_recs_per_card"] = RECOMMENDED_TAGS_COUNT
 
             // default to requesting the dailyprompt and wordpress tags if the user isn't following any tags,
-            // otherwise pass no tags and let the backend supply the user's followed tags. note that we
-            // filter out the dailyprompt tag since new users have that tag followed by default.
+            // otherwise pass the user's followed tags. note we filter out the dailyprompt tag when doing
+            // our empty comparison since new users have that tag followed by default.
             val userTags = getFollowedTagsUseCase.get()
             if (userTags.filterNot { it.tagSlug == BLOGGING_PROMPT_TAG }.isEmpty()) {
                 params["tags"] = "$BLOGGING_PROMPT_TAG,wordpress"
+            } else {
+                params["tags"] = userTags.joinToString(",") { it.tagSlug }
             }
 
             when (taskType) {