Add system property to indicate it supports two active modems.

Bug: 141023026
Test: manual
Change-Id: Iebc2c5e74ab5b7b96b5af9657354836b73f6d7c7
diff --git a/device.mk b/device.mk
index d77d3b3..974de32 100644
--- a/device.mk
+++ b/device.mk
@@ -316,6 +316,9 @@
     vendor.rild.libpath=/vendor/lib64/libril-qc-hal-qmi.so \
     ro.hardware.keystore_desede=true \
 
+PRODUCT_PRODUCT_PROPERTIES += \
+    ro.telephony.max.active.modems=2
+
 # Disable snapshot timer
 PRODUCT_PROPERTY_OVERRIDES += \
     persist.vendor.radio.snapshot_enabled=0 \