fix: default behavior should be to load sample data

Author: angela-tran

benefits/core/migrations/0002_sample_data.py

@@ -8,7 +8,7 @@
 
 
 def load_sample_data(app, *args, **kwargs):
-    if os.environ.get("DJANGO_LOAD_SAMPLE_DATA", "false").lower() == "false":
+    if os.environ.get("DJANGO_LOAD_SAMPLE_DATA", "true").lower() == "false":
         print("  DJANGO_LOAD_SAMPLE_DATA is set to False, skipping sample data")
         return