FP4: Update props from FP4.SP21.B.048.20230215

* Cleanup while we are at it

Change-Id: I2fac1320793e4f9f30f21bf9fb30f1b7293e82c3
diff --git a/system_ext.prop b/system_ext.prop
new file mode 100644
index 0000000..6030f23
--- /dev/null
+++ b/system_ext.prop
@@ -0,0 +1,6 @@
+# DPM
+persist.vendor.dpm.feature=11
+
+# Telephony
+ro.telephony.sim_slots.count=2
+telephony.active_modems.max_count=2