RootCanal: Add a scripted_beacon_test

Test: window 1:
        cd $ANDROID_BUILD_TOP/vendor_libs/test_vendor_lib
        $ANDROID_BUILD_TOP/out/host/linux-x86/bin/root-canal
      window 2:
        cd $ANDROID_BUILD_TOP/vendor_libs/test_vendor_lib
        python3 scripts/test_channel.py 6401 < \
               scripts/scripted_beacon_test_add_beacon
      window 3:
        cd $ANDROID_BUILD_TOP/vendor_libs/test_vendor_lib
        python3 scripts/hci_socket.py 6402
        le_scan 1
Tag: #gd-refactor
Bug: 154491371
Bug: 158019041
Change-Id: Ie37742ccc62e502f6c5c68c8a66b379511469f52