show the caller as Unknown caller in case we know nothing about him

app/src/main/kotlin/com/simplemobiletools/contacts/pro/activities/CallActivity.kt

@@ -85,7 +85,7 @@ class CallActivity : SimpleActivity() {
 
     private fun updateOtherPersonsInfo() {
         val callContact = CallManager.getCallContact(applicationContext) ?: return
-        caller_name_label.text = callContact.name
+        caller_name_label.text = if (callContact.name.isNotEmpty()) callContact.name else getString(R.string.unknown_caller)
         caller_number_label.text = callContact.number
         caller_number_label.beVisibleIf(callContact.number.isNotEmpty())
 

app/src/main/res/values/strings.xml

@@ -113,6 +113,7 @@
 
     <string name="accept">Accept</string>
     <string name="decline">Decline</string>
+    <string name="unknown_caller">Unknown caller</string>
 
     <!-- Speed dial -->
     <string name="speed_dial">Speed dial</string>