Revert "wfd: release wifi p2p resource on disconnecting from WFD service."

This reverts commit fa0aeee6.
Reason for revert: during the disconnection, there are still codes using WifiP2pService.

Bug: 184504089
Test: execute "adb shell setprop persist.debug.wfd.enable 1" and restart the DUT
Change-Id: I0f5a31e072e31fb10f0efe667caa6a6d85942867