[Security solution][Alerts] Fix alerts page controls (elastic#236756)

## Summary

Fixes elastic#231286 

## 🛑 Problem overview

As explained in the linked ticket above, there is a bug on the alert's
page controls (the filters on top of the page).

Basically, after the user re-orders and edits the available controls
(e.g. removes a field) and then tries to reset the controls, some of the
controls gets duplicated.

It doesn't happens always, but only with a specific combination of
edits. The one described in the ticket is:
 - move the "status" control to the end
 - delete the "user" control
 - save, then reset the controls

The result of this is a duplicated "host" control where the "user"
control should be.

## 💡 Solution

The issue appear to lie on the reset callback. 

In this callback there's a loop that goes through the `initialControls`,
which are the ones displayed by default before any user modification.

In this loop, a new "controls state" get generated, but somehow the code
also calls `controlGroup?.updateInput(newInput);` on every loop.

This doesn't make sense, as we are building the state and we want to set
it only once we have it all.

Moving `controlGroup?.updateInput(newInput);` outside of the loop seems
to have solve the issue.

## 💭 To keep in mind

I myself don't fully understand why this fix is working. I tried to deep
dive into the `controlGroup` APIs but it was too deep a rabbit hole for
me to follow

Also, this PR seems to be fixing also another related bug: elastic#226987

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

Author: NicholasPeretti

src/platform/packages/shared/kbn-alerts-ui-shared/src/alert_filter_controls/context_menu.tsx

@@ -70,8 +70,8 @@ export const FilterGroupContextMenu = () => {
         },
         String(counter)
       );
-      controlGroup?.updateInput(newInput);
     }
+    controlGroup?.updateInput(newInput);
 
     switchToViewMode();
     setShowFiltersChangedBanner(false);

src/platform/packages/shared/kbn-alerts-ui-shared/src/alert_filter_controls/filter_group.test.tsx

@@ -471,7 +471,7 @@ describe(' Filter Group Component ', () => {
       fireEvent.click(screen.getByTestId(TEST_IDS.CONTEXT_MENU.RESET));
 
       // blanks the input
-      await waitFor(() => expect(controlGroupMock.updateInput.mock.calls.length).toBe(5));
+      await waitFor(() => expect(controlGroupMock.updateInput.mock.calls.length).toBe(1));
     });
 
     it('should restore controls saved in local storage', async () => {