Prepare for refactoring wifi ipserver start/stop

This is a preparing change.
1) In enableWifiIpServing, replace
   ensureIpServerStarted(ifname) +
   changeInterfaceState(ifname, ipServingMode)
   with enableIpServing(TETHERING_WIFI, ifname, ipServingMode).

   And checking whether corresponding wifi or p2p feature is
   avaialble before enableWifiIpServing. Note: If the wifi or p2p
   feature wasn't supported before, it would still call
   changeInterfaceState without ipServer created but
   changeInterfaceState would be no-op because there is no
   corresponding ipServer for changing state.

2) Splitting enableWifiIpServing into enableWifiIpServing and
   enableWifiP2pIpServing.

3) No longer guess the interface name after T. WIFI_AP_STATE_CHANGED
   intent should always include ifname and it should be tracked by
   mTetherStates. If OEM have modification in wifi framework to send
   empty ifname, tethering no longer support this after T.

4) After T, tethering always trust the ifname which pass by wifi or p2p
   intent broadcast and treat it as TETHERING_WIFI or
   TETHERING_WIFI_P2P. This allow tethering to deprecate wifi/p2p regexs
   after T.

Bug: 189410000
Bug: 178116595
Bug: 185451791
Bug: 190145323
Bug: 176048959

Test: atest TetheringTests

Change-Id: Ia5f69ddf2d842536ce0df75eeae57866f56df571
(cherry picked from commit f2e9409f55a71846d5ec2dd120ba83e3b3773d09)
Merged-In: Ia5f69ddf2d842536ce0df75eeae57866f56df571

0 files changed, 0 insertions, 0 deletions