[illia-sapryga]

Two related changes to one tool.

The docstring says include_in_conversions_metric is mutable on update. It isn't. On a real account Google answered IMMUTABLE_FIELD at apply, after the validate-only dry run had passed, so the preview and the dry run both looked fine and only the real apply failed. Google derives the value from primary_for_goal and whether the goal of the action's category is biddable. The draft now refuses the parameter and names those two instead. I kept the parameter so a caller gets that message and not a schema error. A plan already stored with the field raises at apply and sends nothing. The create tool's docs pointed at the update tool for this, so I corrected those too.

That leaves a gap: an action in a category whose goal isn't biddable has no way to start counting through AdLoop. category closes it by moving the action to another goal, for example DEFAULT to PHONE_CALL_LEAD. The preview shows current_category and warns that campaigns bidding on those goals can start or stop optimizing toward it. The same category, a removed action and an unknown ID are refused at draft time.

What it does not do: it doesn't change primary_for_goal, and it doesn't check whether the target goal is biddable, so the warning says "only if". There is no re-check of the category at apply; the tool's other fields have none either. I left the rules file alone because these tools aren't listed there and the refusal message explains itself.

Tested with the full suite. test_include_in_conversions_metric_is_mutable_on_update and test_update_include_in_conversions_metric_fieldmask asserted the old behaviour and are replaced by tests of the refusal. The category path runs through confirm_and_apply(dry_run=True) with real protos, the real validate-only wrapper and a fake service, and GAQL is stubbed. I saw the IMMUTABLE_FIELD answer on a live account, but this code has not been run against one, and validate-only is known not to catch that particular error, so a green dry run says little about real updates to this tool.