ToneGenerator: fix dual sim ringback tone

If dual sim device has two SIM cards inserted,
in airplane mode it sets "gsm.operator.iso-country" prop
to a single comma, which prevents ToneGenerator to access
prop for "gsm.sim.operator.iso-country" - SIM provider
country code. When VoWifi is used to make a call,
incorrect ringback tone is being played (generic one),
instead if one being read from gsm.sim.operator.iso-country.

This patch fix this, and allows ToneGenerator to correctly
recognize SIM country code.

Bug: 65859291
Test: Check ringback tone during SIM2 VoWiFi in flight mode

Change-Id: Ibb57d38432f3d99f2eac568aec2a949af5e2a9cd

media/libaudioclient/ToneGenerator.cpp

@@ -864,6 +864,13 @@ ToneGenerator::ToneGenerator(audio_stream_type_t streamType, float volume, bool
     if (property_get("gsm.operator.iso-country", value, "") == 0) {
         property_get("gsm.sim.operator.iso-country", value, "");
     }
+    // If dual sim device has two SIM cards inserted and is not registerd to any network,
+    // "," is set to "gsm.operator.iso-country" prop.
+    // In this case, "gsm.sim.operator.iso-country" prop should be used.
+    if (strlen(value) == 1 && strstr(value, ",") != NULL) {
+        property_get("gsm.sim.operator.iso-country", value, "");
+    }
+
     if (strstr(value, "us") != NULL ||
         strstr(value, "ca") != NULL) {
         mRegion = ANSI;