Expose wifi p2p toggle switch to user

We will not show the Wifi p2p settings to user but the turn on/off capability
is exposed to the user and applications will be expected to let user turn on
and turn off p2p at launch.

Remove the compound button integration from the settings page.

Bug: 5242230
Change-Id: I54ec307304256b051e85201b8bb829d0e5544bfc