Init project.

example/android/app/src/main/java/com/example/MainActivity.java

@@ -0,0 +1,15 @@
+package com.example;
+
+import com.facebook.react.ReactActivity;
+
+public class MainActivity extends ReactActivity {
+
+  /**
+   * Returns the name of the main component registered from JavaScript. This is used to schedule
+   * rendering of the component.
+   */
+  @Override
+  protected String getMainComponentName() {
+    return "example";
+  }
+}