Tweaked tests to be more solid for sparse

Conflicts:
	solr/core/src/java/org/apache/solr/request/DocValuesFacets.java
	solr/core/src/java/org/apache/solr/request/SimpleFacets.java
Cherry pick resolving

Conflicts:
	solr/core/src/java/org/apache/solr/request/DocValuesFacets.java