gn2bp: Update the comment for value args and list args

Test: ./update_results.sh
Change-Id: I0f28041f0c6e83ff9dd20c74b0a4dbd684b3f2e0
diff --git a/tools/gn2bp/gen_android_bp b/tools/gn2bp/gen_android_bp
index 7050216..5a49d4f 100755
--- a/tools/gn2bp/gen_android_bp
+++ b/tools/gn2bp/gen_android_bp
@@ -627,10 +627,9 @@
   # - flags (--flag)
   # - value args (--arg value)
   # - list args (--arg value1 --arg value2)
+  # value args have exactly one arg value pair and list args have one or more arg value pairs.
   # Note that the set of list args contains the set of value args.
-  # value args must have exactly one arg value pair but list args could have one arg value pair.
-  # This is because list args with one arg value pair and value args can not be distinguished only
-  # from the desc.json
+  # This is because list and value args are identical when the list args has only one arg value pair
   # Some functions provide special implementations for each type, while others
   # work on all of them.
   def _has_arg(self, arg):