Fix the extra speaking in Allow supervision dialog

- Extra speaking the  "double tap to activate" when focus
  "Family Link manage ...".
- Root cause: this Textview set the setMovementMethod method.
- Solution: Remove this setMovementMethod because it is usless in here.

Bug: 187968203
Test: manual test
Change-Id: Ia3f277f6814cb009f0e07f56381e3e46fbacc7a8