Refactor get_keys_from_config for simpler conditionals

Author: djhoese

satpy/dataset/id_keys.py

@@ -7,13 +7,13 @@
 import numpy as np
 
 
-def get_keys_from_config(common_id_keys, config):
+def get_keys_from_config(common_id_keys: dict, config: dict) -> dict:
     """Gather keys for a new DataID from the ones available in configured dataset."""
     id_keys = {}
     for key, val in common_id_keys.items():
-        if key in config:
-            id_keys[key] = val
-        elif val is not None and (val.get("required") is True or val.get("default") is not None):
+        has_key = key in config
+        is_required_or_default = val is not None and (val.get("required") is True or val.get("default") is not None)
+        if has_key or is_required_or_default:
             id_keys[key] = val
     if not id_keys:
         raise ValueError("Metadata does not contain enough information to create a DataID.")