Remove policy transparency for cross-profile calendar setting

We will likely deprecate this setting in the next release, to be
replaced by usage of 'connected work and personal apps'. However, we are
keeping it in this release as it's still possible that a lightweight
calendar access API could be useful, if the admin and user approvals are
combined.

For now, the error message that refers to cross-profile calendar when
the setting is disabled is confusing admins, since we're not
recommending usage of this API at this time.

Remove the setting when it is disabled, rather than showing policy
transparency.

Fixes: 143477431
Test: manual
Change-Id: I65573a5ba892e12a4dabcdf23541f33516db0a8a