Switch to GameActivity and gradle build

Fixes: https://github.com/damus-io/notedeck/issues/189
Fixes: https://github.com/damus-io/notedeck/issues/190
Signed-off-by: William Casarin <jb55@jb55.com>

crates/notedeck_chrome/android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <application
+        android:allowBackup="true"
+        android:label="Notedeck"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.MaterialComponents.DayNight.NoActionBar">
+        <activity
+            android:name=".MainActivity"
+            android:configChanges="orientation|screenSize|screenLayout|keyboardHidden"
+            android:exported="true"
+            android:launchMode="singleTask"
+        >
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+
+            <meta-data
+                android:name="android.app.lib_name"
+                android:value="main" />
+        </activity>
+    </application>
+
+[[package.metadata.android.uses_feature]]
+name = "android.hardware.vulkan.level"
+required = true
+version = 1
+
+    <uses-feature android:name="android.hardware.vulkan.level"
+                  android:required="true"
+                  android:version="1" />
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+</manifest>

crates/notedeck_chrome/android/app/src/main/java/com/damus/notedeck/MainActivity.java

@@ -0,0 +1,54 @@
+package com.damus.notedeck;
+
+import android.os.Bundle;
+import android.util.Log;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.core.graphics.Insets;
+import androidx.core.view.DisplayCutoutCompat;
+import androidx.core.view.ViewCompat;
+import androidx.core.view.WindowCompat;
+import androidx.core.view.WindowInsetsCompat;
+
+import com.google.androidgamesdk.GameActivity;
+
+public class MainActivity extends GameActivity {
+  static {
+    System.loadLibrary("main");
+  }
+
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+      // Shrink view so it does not get covered by insets.
+
+      View content = getWindow().getDecorView().findViewById(android.R.id.content);
+      ViewCompat.setOnApplyWindowInsetsListener(content, (v, windowInsets) -> {
+        Insets insets = windowInsets.getInsets(WindowInsetsCompat.Type.systemBars());
+
+        ViewGroup.MarginLayoutParams mlp = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
+        mlp.topMargin = insets.top;
+        mlp.leftMargin = insets.left;
+        mlp.bottomMargin = insets.bottom;
+        mlp.rightMargin = insets.right;
+        v.setLayoutParams(mlp);
+
+        return WindowInsetsCompat.CONSUMED;
+      });
+
+      WindowCompat.setDecorFitsSystemWindows(getWindow(), true);
+
+      super.onCreate(savedInstanceState);
+  }
+
+  @Override
+  public boolean onTouchEvent(MotionEvent event) {
+      // Offset the location so it fits the view with margins caused by insets.
+
+      int[] location = new int[2];
+      findViewById(android.R.id.content).getLocationOnScreen(location);
+      event.offsetLocation(-location[0], -location[1]);
+      return super.onTouchEvent(event);
+  }
+}