s4-common: remove deprecated BLUETOOTH_HCI_USE_MCT flag

Change-Id: Icebec852922f579deba3f05f4f80ba68f40bd958
s4-common: use bluetooth.hciattach property and updated bt.sh

PatchSet 1: initial commit
PatchSet 2: re-add license
PatchSet 3: add to common-proprietary-files.txt

Change-Id: I565b2db94887854df1704b2f8c47236283241a19
Merge "s4-common: use bluetooth.hciattach property and updated bt.sh" into cm-10.2
Merge remote-tracking branch 'upstream/cm-10.2' into cm-10.2