Introduce workaround for libgdx issue by @codegist

libgdx/libgdx#3861 libgdx/libgdx#4626 libgdx/libgdx#5312

android/src/io/anuke/mindustry/PatchedAndroidApplication.java

@@ -0,0 +1,25 @@
+package io.anuke.mindustry;
+
+import com.badlogic.gdx.backends.android.AndroidApplication;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class PatchedAndroidApplication extends AndroidApplication {
+
+    private final ExecutorService exec = Executors.newSingleThreadExecutor();
+    private final Runnable forcePause = new Runnable() {
+        @Override
+        public void run() {
+            try {Thread.sleep(100);} catch (InterruptedException e) {}
+            graphics.onDrawFrame(null);
+        }
+    };
+
+    @Override
+    protected void onPause () {
+        if(useImmersiveMode) {
+            exec.submit(forcePause);
+        }
+        super.onPause();
+    }
+}