Move threadnetwork HAL to VAPEX

com.android.hardware.threadnetwork is a new VAPEX containing
threadnetwork HAL. It also includes ot-rcp.

Bug: 296966113
Test: vts-tf > run vts -m VtsHalTheadNetworkTargetTest
Change-Id: Id2028d755f9b0dcc06ccd817bddf3195efb5595b
diff --git a/threadnetwork/aidl/default/file_contexts b/threadnetwork/aidl/default/file_contexts
new file mode 100644
index 0000000..39ba3b5
--- /dev/null
+++ b/threadnetwork/aidl/default/file_contexts
@@ -0,0 +1,4 @@
+(/.*)?                                                      u:object_r:vendor_file:s0
+/etc(/.*)?                                                  u:object_r:vendor_configs_file:s0
+/bin/hw/android\.hardware\.threadnetwork-service            u:object_r:hal_threadnetwork_default_exec:s0
+/bin/ot-rcp                                                 u:object_r:ot_rcp_exec:s0