Uninitialized UiAutomationConnection incorrectly enforces caller id.

When a client of a UiAutomationConnection is set it remembers its UID
and allows subsequent operations only from this UID. The connection
If the connection was not used, i.e. its client is not set, and an
attempt to destroy it is made the connection enforces the caller UID
to be that of the owner but it does not have an owner yet. Now if the
destroy method is called on a connection that is never used (has no
client) we do not enforce caller UID.

bug:11465888

Change-Id: I739dfc45e772ea970b6ab384e4420184724333a3