android-native: SDL3 APK build for the native client

build-android-native.sh downloads SDL 3.4.16 (sha256-checked), builds
libSDL3.so and libmain.so (native_render + port_platform + embedded
Python) at API 24, and wraps them in the SDLActivity shell under
android-native/ (package org.metin2port.client). push-android-client.sh
copies the 40250 Client directory into the app's files/ with run-as
(--locale XX selects locale_XX.cfg). port_logic links with
--no-dependent-libraries on ELF targets so the verbatim
`#pragma comment(lib, ...)` lines do not break lld.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android-native/settings.gradle

@@ -0,0 +1,15 @@
+pluginManagement {
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+dependencyResolutionManagement {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+rootProject.name = 'metin2-native'
+include ':app'