Fix UI location and snackbar padding for RTL.

Screenshots:
- Padding: https://screenshot.googleplex.com/3yd42n8MzSaw7Xv
- LTR portrait: https://screenshot.googleplex.com/5uskVaFs5hPHxod
- RTL portrait: https://screenshot.googleplex.com/4zn8Ds76TXZF7BP
- LTR landscape: https://screenshot.googleplex.com/5GQFYN5MTiJWxyB
- RTL landscape: https://screenshot.googleplex.com/ANmwpmf2A53GE5D

Fix: 276298668
Fix: 276236465
Test: Change device to RTL locale, open and interact with the
      AccessibilityMenu service.
Change-Id: I1633840bae0da0a576efb16d9d45659083deb1b9