when disconnectHeadsetInternal, allow it when the BT is not disabled
when disconnectHeadsetInternal, allow it when the BT is not disabled

The old code allowed the disconnection only when BT is enabled. This
caused a bug during BT turning off that Headset connection failed
to disconnect.
Change-Id: Iba15a1595b6987064f071ad90bbb126a6edfe6b5

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base