LE-COC: Free LE-COC server resource when BluetoothServerSocket is closed

* When BluetoothServerSocket is closed in the Java layer, the native
  layer should respond by freeing all resources used by the server
  including file descriptors, structs, PSMs, and security IDs
* We did this correctly for BR_EDR L2CAP COC channels after
  I4e37dcd858af258fbd64fbfb2fbf0083bd743e06, but the same fix did not
  apply to LE COC
* This CL make sure LE COC server resources are freed propertly upon
  server fd closure

Test: open and close LE COC server repeatedly on an Android phone
Bug: 144148429
Change-Id: I16fa10e77612105d23848f71925ff6efc95bc75a