Unify installer context to be 'installer'
'install' was being used in some places.
The context can be used to limit what configuration is
used for a given request so having consistency is
valuable.
This affected the force_schema_updates value in LDAPClient
which looks for api.env.context in ('installer', 'updates')
Related: https://pagure.io/freeipa/issue/8798
Signed-off-by: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Rafael Guterres Jeffman <rjeffman@redhat.com>