This is a follow-up to #123998 which fixed autokeying on objects when
the "Only Insert Needed" user preference was enabled. This fixes an
essentially identical bug for auto-keying bones, but *also* fixes a
different-but-related bug unique to bone keying.
In the first bug the location channel would erroneously not get keyed
sometimes when the "Only Insert Needed" user preference was enabled.
This fixes that by passing in whether more than one bone is being keyed
or not, and using that to accurately determine if location actually
needs to be keyed.
In the second bug, the location channel would erroneously not get keyed
when "Auto IK" was used to transform bones. This fixes that by just
being over-conservative. This unforunately leads to more bones getting
their location channel keyed than needed when Auto IK is used, but this
is better than *failing* to key needed channels, which was the previous
behavior. I left a comment explaining the situation, along with a TODO
to address this in a more satisfying way in the future.
Pull Request: https://projects.blender.org/blender/blender/pulls/124054
b31d34033a