Use the ?= operator so BT properties can be overridden

System properties set with the "=" operator cannot be overriden. This
device is used elsewhere in the system and some of the properties need
to be overridden. The "?=" operator will use the assigned value if no
other values are assigned elsewhere, allowing for overrides.

Bug: 230638462
Test: adb shell getprop | grep bluetooth
Change-Id: I12dfdf4830e041b2c4e50eb8136ac0fb7146cc8e
(cherry picked from commit 92f2c0e6a3fcbd63ad1805e78e3bc50c46d2ba45)
diff --git a/device.mk b/device.mk
index c3c52f3..03f8412 100644
--- a/device.mk
+++ b/device.mk
@@ -292,27 +292,27 @@
 # Bluetooth Properties
 # Set supported Bluetooth profiles to enabled
 PRODUCT_PRODUCT_PROPERTIES += \
-	bluetooth.profile.asha.central.enabled=true \
-	bluetooth.profile.a2dp.source.enabled=true \
-	bluetooth.profile.avrcp.target.enabled=true \
-	bluetooth.profile.bap.broadcast.assist.enabled=true \
-	bluetooth.profile.bap.unicast.client.enabled=true \
-	bluetooth.profile.bas.client.enabled=true \
-	bluetooth.profile.csip.set_coordinator.enabled=true \
-	bluetooth.profile.gatt.enabled=true \
-	bluetooth.profile.hap.client.enabled=true \
-	bluetooth.profile.hfp.ag.enabled=true \
-	bluetooth.profile.hid.device.enabled=true \
-	bluetooth.profile.hid.host.enabled=true \
-	bluetooth.profile.map.server.enabled=true \
-	bluetooth.profile.mcp.server.enabled=true \
-	bluetooth.profile.opp.enabled=true \
-	bluetooth.profile.pan.nap.enabled=true \
-	bluetooth.profile.pan.panu.enabled=true \
-	bluetooth.profile.pbap.server.enabled=true \
-	bluetooth.profile.sap.server.enabled=true \
-	bluetooth.profile.ccp.server.enabled=true \
-	bluetooth.profile.vcp.controller.enabled=true
+	bluetooth.profile.asha.central.enabled?=true \
+	bluetooth.profile.a2dp.source.enabled?=true \
+	bluetooth.profile.avrcp.target.enabled?=true \
+	bluetooth.profile.bap.broadcast.assist.enabled?=true \
+	bluetooth.profile.bap.unicast.client.enabled?=true \
+	bluetooth.profile.bas.client.enabled?=true \
+	bluetooth.profile.csip.set_coordinator.enabled?=true \
+	bluetooth.profile.gatt.enabled?=true \
+	bluetooth.profile.hap.client.enabled?=true \
+	bluetooth.profile.hfp.ag.enabled?=true \
+	bluetooth.profile.hid.device.enabled?=true \
+	bluetooth.profile.hid.host.enabled?=true \
+	bluetooth.profile.map.server.enabled?=true \
+	bluetooth.profile.mcp.server.enabled?=true \
+	bluetooth.profile.opp.enabled?=true \
+	bluetooth.profile.pan.nap.enabled?=true \
+	bluetooth.profile.pan.panu.enabled?=true \
+	bluetooth.profile.pbap.server.enabled?=true \
+	bluetooth.profile.sap.server.enabled?=true \
+	bluetooth.profile.ccp.server.enabled?=true \
+	bluetooth.profile.vcp.controller.enabled?=true
 
 # Set the Bluetooth Class of Device
 # Service Field: 0x5A -> 90