Bluetooth: add system property for HID transport selection

Add property bluetooth.core.le.dsa_transport_preference containing a
list of supported HID transport protocols for IMU data over LE Audio by
order of preference:

Bug: 307588546
Test: make
Change-Id: I7aef404a2c6c8cc872efb994e328a175d5b4efd4
diff --git a/private/property_contexts b/private/property_contexts
index 6d1c2f6..1b7a755 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -622,6 +622,7 @@
 
 bluetooth.core.le.vendor_capabilities.enabled        u:object_r:bluetooth_config_prop:s0 exact bool
 bluetooth.sco.disable_enhanced_connection            u:object_r:bluetooth_config_prop:s0 exact bool
+bluetooth.core.le.dsa_transport_preference           u:object_r:bluetooth_config_prop:s0 exact string
 
 persist.nfc.debug_enabled                      u:object_r:nfc_prop:s0 exact bool
 persist.nfc.vendor_debug_enabled               u:object_r:nfc_prop:s0 exact bool