WifiManager: get startLOHS packageName

When an application calls startLocalOnlyHotspot, we need to send the
package name from the manager-side of the call.  This CL updates the
call to WifiServiceImpl.startLocalOnlyHotspot and the relevant aidl
file.

Bug: 31466854
Test: frameworks/base/wifi/tests/runtests.sh
Change-Id: I1dd0142dc58c767336c9323986d20e38bf11220d