WifiServiceImpl: Allow car dock app to toggle wifi on

Add an exception to allow the default car dock app to toggle wifi on,
but do not allow them to toggle wifi off.

Bug: 121046553
Test: ./frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: Ice2635f3420c1a2c4f30d0d6e353f18840f0626c
2 files changed