Spatial audio: add property for spatializer effect

Ignore-AOSP-First: confidential feature

Add a property to be read by system_server's AudioService that
indicates whether a spatializer effect is available on the device.
If true, spatialization functionality will be initialized.

Bug: 188502620
Test: adb shell dumpsys audio | grep -A 4 Spatial
Change-Id: I759e2fb32087b6e8e2a578b6ec804fb7c4f1d4f1
diff --git a/private/property_contexts b/private/property_contexts
index 6f1cbe0..b691cf3 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -323,6 +323,9 @@
 ro.audio.ignore_effects   u:object_r:audio_config_prop:s0 exact bool
 ro.audio.monitorRotation  u:object_r:audio_config_prop:s0 exact bool
 ro.audio.offload_wakelock u:object_r:audio_config_prop:s0 exact bool
+# Boolean property used in AudioService to configure whether
+# spatializer functionality should be initialized
+ro.audio.spatializer_enabled u:object_r:audio_config_prop:s0 exact bool
 
 persist.config.calibration_fac u:object_r:camera_calibration_prop:s0 exact string