Add tetheroffload HAL APEX

This is used by Cuttlefish as of now.

Bug: 300011461
Test: VtsHalTetheroffloadTargetTest
Change-Id: I3cd83d4011636e1ebfca5d20ed4ff7c527d5a63f
diff --git a/tetheroffload/aidl/default/apex_manifest.json b/tetheroffload/aidl/default/apex_manifest.json
new file mode 100644
index 0000000..4c90889
--- /dev/null
+++ b/tetheroffload/aidl/default/apex_manifest.json
@@ -0,0 +1,4 @@
+{
+    "name": "com.android.hardware.tetheroffload",
+    "version": 1
+}