[REF] Remove wrangling on activityType param

[eileenmcnaughton]

Overview

Removes an almost-redundant parameter & fixes the last place where it is still passed in

Before

Function called only from civi core & activityType almost always passed in (screenshot from slightly outdated civi-universe - in fact one of the 2 nulls is already fixed

After

Technical Details

There is only 1 remaining place that calls this function & does not specifiy activityType. This fixes
that place to pass in activityType and stops attempting to calculate activityType
based on in-function guess work

Comments

[civibot]

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[eileenmcnaughton]

test this please

[demeritcowboy]

I had looked at the recent related PR, and did a grep on core here and this looks ok to me.

[eileenmcnaughton]

@seamuslee001 ok to merge based on ^^ ?