chore(mobile-next): Android Gradle 堆改为 4096M

-Xmx1536M 无法完成 release 构建（Java heap space）。本机以 -Xmx4096M 真实打通 debug/release，作为当前项目稳定值入库。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>
Co-authored-by: Cursor <cursoragent@cursor.com>

mobile-next/android/gradle.properties

@@ -1,3 +1,3 @@
-org.gradle.jvmargs=-Xmx1536M
+org.gradle.jvmargs=-Xmx4096M
 android.useAndroidX=true
 android.enableJetifier=true