Separate stub Magisk Manager to a module

app/src/main/java/a/a.java

@@ -0,0 +1,13 @@
+package a;
+
+import com.topjohnwu.magisk.utils.PatchAPK;
+import com.topjohnwu.signing.BootSigner;
+
+import androidx.annotation.Keep;
+
+@Keep
+public class a extends BootSigner {
+    public static boolean patchAPK(String in, String out, String pkg) {
+        return PatchAPK.patch(in, out, pkg);
+    }
+}