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
diff --git a/android/variable.go b/android/variable.go
index e6abee6..271454a 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -138,6 +138,10 @@
 	SanitizeDeviceArch []string `json:",omitempty"`
 
 	ArtUseReadBarrier *bool `json:",omitempty"`
+
+	BtConfigIncludeDir *string `json:",omitempty"`
+	BtHcilpIncluded    *string `json:",omitempty"`
+	BtHciUseMct        *bool   `json:",omitempty"`
 }
 
 func boolPtr(v bool) *bool {