Allow to fix broken DM mode

SeekBar sets its stateDescription to the progress recently, which causes
DM mode to fail since RotaryService also uses stateDescription to decide
whether the SeekBar is a DM view. The fix is to let RotaryService uses
contentDescription instead.

Bug: 183424213
Test: manual
Change-Id: Ief3abb9d9b1c343c70bc446d482598ca8faef4e2
1 file changed