fix(tablet): fix a11y button gesture assets to match new fancy ones on other a11y preferences

Fix: 269717670
Test: 1. Go to Settings > Accessibility shortcuts > accessibility button & gesture.
2. Observe The Gesture's picture.
3. Go to any other accessibility's shortcut.
4. Observe the picture of the Use accessibility gesture. #2 should look like #4

Change-Id: I11f64648412c9795383d356e80d9dd499095f53b