Make a11y clickable span work after node recycle

Services recycle nodes when gathering possible actions
for users to take. It's very confusing for them if they
can't recycle the node without breaking their ability
to activate a clickable span inside it.

Making ClickableSpans used for accessibility independent
of their parent nodes.

Also adjusting the value used for invalid window ids to
come from AccessibilityWindowInfo. I must have missed this
in an earlier cleanup. I needed the value for the spans,
so I figured I might as well use the correct one.

Bug: 37004527
Test: Now recycling the node in the a11y cts test.
Change-Id: I6de4e98a182dd43c4fcd0430a3c082fcc8e458c7