Added 4th telemetry port option

app/src/main/java/sq/rogue/rosettadrone/MainActivity.java

@@ -1850,6 +1850,12 @@ public class MainActivity extends AppCompatActivity implements OnMapReadyCallbac
                 int port = Integer.parseInt(Objects.requireNonNull(mainActivityRef.prefs.getString("pref_telemetry_3_port", "")));
                 mainActivityRef.mMavlinkReceiver.mavLinkConnections.add(new MAVLinkConnection(host, port));
             }
+
+            if (mainActivityRef.prefs.getBoolean("pref_telemetry_4_enabled", false)) {
+                String host = mainActivityRef.prefs.getString("pref_telemetry_4_host", "");
+                int port = Integer.parseInt(Objects.requireNonNull(mainActivityRef.prefs.getString("pref_telemetry_4_port", "")));
+                mainActivityRef.mMavlinkReceiver.mavLinkConnections.add(new MAVLinkConnection(host, port));
+            }
         }
 
         protected void close() {

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

@@ -101,6 +101,10 @@
     <string name="pref_telemetry_3_host">Host 3</string>
     <string name="pref_telemetry_3_port">Port 3</string>
 
+    <string name="pref_telemetry_4_enabled">Enable Telemetry 4</string>
+    <string name="pref_telemetry_4_host">Host 4</string>
+    <string name="pref_telemetry_4_port">Port 4</string>
+
     <string name="pref_video_ip">Video IP address</string>
     <string name="pref_video_port">Video port</string>
     <string name="pref_video_bitrate">Video bitrate</string>

app/src/main/res/xml/preferences.xml

@@ -253,6 +253,23 @@
             android:key="pref_telemetry_3_port"
             android:title="@string/pref_telemetry_3_port" />
 
+        <androidx.preference.SwitchPreferenceCompat
+            android:defaultValue="false"
+            android:key="pref_telemetry_4_enabled"
+            android:title="@string/pref_telemetry_4_enabled" />
+        <androidx.preference.EditTextPreference
+            android:defaultValue=""
+            android:dependency="pref_telemetry_4_enabled"
+            android:digits="0123456789."
+            android:inputType="number"
+            android:key="pref_telemetry_4_host"
+            android:title="@string/pref_telemetry_4_host" />
+        <androidx.preference.EditTextPreference
+            android:defaultValue=""
+            android:dependency="pref_telemetry_4_enabled"
+            android:key="pref_telemetry_4_port"
+            android:title="@string/pref_telemetry_4_port" />
+
     </PreferenceCategory>
 
     <PreferenceCategory