Revert "Revert "[s5123][device] Change vendor telephony code path""

This reverts commit 479f361d7734b0f77d084892a2f0f7299e23488a.

Reason for revert: Restore 16405845-t-codebase-seperate

Change-Id: Id7f5e8b7e4470416da0002768c3960e554c0cf6c
diff --git a/device-common.mk b/device-common.mk
index 250de1c..cdafd12 100644
--- a/device-common.mk
+++ b/device-common.mk
@@ -14,6 +14,7 @@
 # limitations under the License.
 #
 
+-include vendor/google_devices/gs101/proprietary/telephony/device-vendor.mk
 include device/google/gs101/device.mk
 
 # Telephony