The com.sun.star.accessibility.AccessibleContext UNO service
is unnecessary and not really used for implementing a11y support,
apart from some a11y implementations declaring support for it.
What is relevant is the com.sun.star.accessibility.XAccessibleContext
interface instead.
Stop declaring support for the com.sun.star.accessibility.AccessibleContext
service in AccessibleGridControlBase (and drop related
XServiceInfo::getImplementationName overrides in subclasses),
in preparation of dropping the service altogether in an upcoming
commit.
Change-Id: I66e6390ad77e3ff0febfb335c312954815c6581c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/210400
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>