MediaBrowserCompat: Add a disconnecting state

By adding a CONNECT_STATE_DISCONNECTING, we could prevent
the ConnectionCallback to be called after disconnect().
Also, applied the previous framework change to make
forceCloseConnection() be called in the same thread.

Bug: 36106103
Test: manual using Support4Demos
Change-Id: I1ea2b645c64dee7c9ee26d93f7a2b0d44d41bd99
1 file changed