Detect TCP devices provided by mDNS

Their serial is not in the form ip:port, but rather a complex string
containing "adb-tls-connect".

Fixes #6248 <https://github.com/Genymobile/scrcpy/issues/6248>

app/src/adb/adb_device.c

@@ -39,5 +39,11 @@ sc_adb_device_get_type(const char *serial) {
         return SC_ADB_DEVICE_TYPE_TCPIP;
     }
 
+    // TCP/IP devices provided by mDNS contain "adb-tls-connect"
+    // <https://github.com/Genymobile/scrcpy/issues/6248>
+    if (strstr(serial, "adb-tls-connect")) {
+        return SC_ADB_DEVICE_TYPE_TCPIP;
+    }
+
     return SC_ADB_DEVICE_TYPE_USB;
 }

server/src/main/java/com/genymobile/scrcpy/Server.java

@@ -27,6 +27,8 @@ import com.genymobile.scrcpy.video.VideoSource;
 import android.annotation.SuppressLint;
 import android.os.Build;
 import android.os.Looper;
+import android.system.ErrnoException;
+import android.system.Os;
 
 import java.io.File;
 import java.io.IOException;
@@ -233,6 +235,8 @@ public final class Server {
             }
         });
 
+        dropRootPrivileges();
+
         prepareMainLooper();
 
         Options options = Options.parse(args);
@@ -273,4 +277,17 @@ public final class Server {
             // Do not print stack trace, a user-friendly error-message has already been logged
         }
     }
+
+    @SuppressWarnings("deprecation")
+    private static void dropRootPrivileges() {
+        try {
+            if (Os.getuid() == 0) {
+                // Copy-paste does not work with root user
+                // <https://github.com/Genymobile/scrcpy/issues/6224>
+                Os.setuid(2000);
+            }
+        } catch (Exception e) {
+            Ln.w("Cannot set UID", e);
+        }
+    }
 }