Convert Thermal HIDL to AIDL.

This patch converts Thermal HIDL to AIDL and adds an empty example
implementation.

Bug: b/205762943
Test: atest VtsHalThermalTargetTest
Change-Id: I0c80ac400cc41f50916dbed58bb48f878dfae17f
diff --git a/thermal/aidl/default/thermal-example.rc b/thermal/aidl/default/thermal-example.rc
new file mode 100644
index 0000000..591ca03
--- /dev/null
+++ b/thermal/aidl/default/thermal-example.rc
@@ -0,0 +1,4 @@
+service vendor.thermal-example /vendor/bin/hw/android.hardware.thermal-service.example
+    class hal
+    user nobody
+    group system