[A11Y] Fix MasterSwitchPreference onClick not callback after TalkBack is enabled

TalkBack service dispatches onClick event to the Switch component
instead of the LinearLayout wrapping it. Do all the onClick tasks
for the Switch component instead of the LinearLayout wrapping it.

Bug: 142570671
Test: MasterSwitchPreferenceTest
      Manual click the toggle button for both TalkBack enabled case and disabled case.

Change-Id: I4b2f9df309d03a477863445cd187384cdb61314b