Copy links to orginal text in a11y node info

Not doing this copy results in us keeping
mOriginalText around. That is a CharSequence that
can contains Spans that reference other Views and
other expensive stuff.

Fixes: 78511639
Fixes: 75602764

Test: make
Change-Id: I977646311167f8d13e1c4a5c8fc38372e6d1ff3c