Test: Change allow nulls parameter with with empty on cmts mapper test

Also, this 'SameParameterValue' warning got suppressed for the
'getDefaultCommentList(...)' function as it is currently being used once
and as 'getDefaultCommentList(false)'. How this doesn't mean it will not
be used in the future, or wasn't used in the past. As such, keeping this
method signature and suppressing this warning for the time being seems
to be the better approach here.

Related PR Comment: https://github.com/wordpress-mobile/
WordPress-FluxC-Android/pull/2868#discussion_r1362018044

example/src/test/java/org/wordpress/android/fluxc/common/CommentsMapperTest.kt

@@ -189,32 +189,33 @@ class CommentsMapperTest {
         )
     }
 
-    private fun getDefaultComment(allowNulls: Boolean): CommentEntity {
+    private fun getDefaultComment(withEmpty: Boolean): CommentEntity {
         return CommentEntity(
                 id = 0L,
                 remoteCommentId = 10L,
                 remotePostId = 100L,
                 authorId = 44L,
                 localSiteId = 10_000,
                 remoteSiteId = 100_000L,
-                authorUrl = if (allowNulls) "" else "https://test-debug-site.wordpress.com",
-                authorName = if (allowNulls) "" else "authorname",
-                authorEmail = if (allowNulls) "" else "[email protected]",
-                authorProfileImageUrl = if (allowNulls) "" else "https://gravatar.com/avatar/111222333",
-                postTitle = if (allowNulls) "" else "again",
+                authorUrl = if (withEmpty) "" else "https://test-debug-site.wordpress.com",
+                authorName = if (withEmpty) "" else "authorname",
+                authorEmail = if (withEmpty) "" else "[email protected]",
+                authorProfileImageUrl = if (withEmpty) "" else "https://gravatar.com/avatar/111222333",
+                postTitle = if (withEmpty) "" else "again",
                 status = APPROVED.toString(),
-                datePublished = if (allowNulls) "" else "2021-05-12T15:10:40+02:00",
+                datePublished = if (withEmpty) "" else "2021-05-12T15:10:40+02:00",
                 publishedTimestamp = 1_000_000,
-                content = if (allowNulls) "" else "content example",
-                url = if (allowNulls) "" else "https://test-debug-site.wordpress.com/2021/02/25/again/#comment-137",
+                content = if (withEmpty) "" else "content example",
+                url = if (withEmpty) "" else "https://test-debug-site.wordpress.com/2021/02/25/again/#comment-137",
                 hasParent = true,
                 parentId = 1_000L,
                 iLike = false
         )
     }
 
-    private fun getDefaultCommentList(allowNulls: Boolean): CommentEntityList {
-        val comment = getDefaultComment(allowNulls)
+    @Suppress("SameParameterValue")
+    private fun getDefaultCommentList(withEmpty: Boolean): CommentEntityList {
+        val comment = getDefaultComment(withEmpty)
         return listOf(
                 comment.copy(id = 1L, remoteCommentId = 10L, datePublished = "2021-07-24T00:51:43+02:00"),
                 comment.copy(id = 2L, remoteCommentId = 20L, datePublished = "2021-07-24T00:51:43+02:00"),