Add contexthub HAL APEX

It's typical to make the HAL binary to link its dependencies statically
to make the resulting APEX smaller. Will do it as a follow-up.

Bug: 297467264
Test: VtsAidlHalContextHubTargetTest
Change-Id: Icbc558d81a473b5ea01d2d0b5f7090fcb5365085
diff --git a/contexthub/aidl/default/android.hardware.contexthub-service.example.rc b/contexthub/aidl/default/android.hardware.contexthub-service.example.rc
new file mode 100644
index 0000000..7d5d2aa
--- /dev/null
+++ b/contexthub/aidl/default/android.hardware.contexthub-service.example.rc
@@ -0,0 +1,4 @@
+service vendor.contexthub-default /apex/com.android.hardware.contexthub/bin/hw/android.hardware.contexthub-service.example
+    class hal
+    user context_hub
+    group context_hub