Add Android.bp variables to the soong build parser

* BtConfigIncludeDir: BOARD_BLUETOOTH_BDROID_BUILDCFG_INCLUDE_DIR
* BtHcilpIncluded: BOARD_BLUETOOTH_BDROID_HCILP_INCLUDED
* BtHciUseMct: BLUETOOTH_HCI_USE_MCT

Bug: 32958753
Test: Code compilation, no user visible effects

Change-Id: I0dc53172ee823e4e0fa69749e1297713796538cf