bluetooth: add function to read bt_pkg_version

BUG=b:146437436
TEST=Tested locally

Cq-Depend: 1972201
Change-Id: I652a8a10653feaac817640892e9c830699605565
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1972694
Commit-Queue: Shijin Abraham <shijinabraham@google.com>
Tested-by: Shijin Abraham <shijinabraham@google.com>
Reviewed-by: Shijin Abraham <shijinabraham@google.com>
Reviewed-by: Daniel Winkler <danielwinkler@google.com>
diff --git a/client/cros/chameleon/chameleon.py b/client/cros/chameleon/chameleon.py
index fe2b6ae..7f9d9d1 100644
--- a/client/cros/chameleon/chameleon.py
+++ b/client/cros/chameleon/chameleon.py
@@ -325,6 +325,11 @@
         self._chameleond_proxy.Reboot()
 
 
+    def get_bt_pkg_version(self):
+        """ Read the current version of chameleond."""
+        return self._chameleond_proxy.get_bt_pkg_version()
+
+
     def _get_log(self):
         """Get log from chameleon. It will be registered by atexit.