sm6250-common: Add debug IMS props to workaround CarrierConfig restrictions

We support IMS features on carriers not listed in the CarrierConfig,
so let's use the props to enable it everywhere.

Change-Id: Id3ad71d522a22048f7ad86d89695ad262361632d

system.prop

@@ -41,6 +41,11 @@ persist.dpm.feature=1
 persist.vendor.cp.taper_term_mv=6500
 persist.vendor.cp.fcc_main_ua=400000
 
+# IMS
+persist.dbg.volte_avail_ovr=1
+persist.dbg.vt_avail_ovr=1
+persist.dbg.wfc_avail_ovr=1
+
 # Media
 debug.stagefright.ccodec=1
 media.settings.xml=/vendor/etc/media_profiles_vendor.xml