[WIFI] Add command shell argument for the 'shared' bit

Add command shell argument to control the WifiConfiguration#shared
argument. Also update the toString() command to print it out.

Bug: 192203602
Test: manually - 'adb shell cmd wifi add-network SomethingOpenPrivate open -p' verify using 'adb shell dumpsys wifi'
Change-Id: I0520081707992b160966902ed7d0b8d01d8788af
2 files changed