Add Java module to keep the screen awake when needed.

src/main/java/io/lbry/browser/reactmodules/UtilityModule.java

@@ -0,0 +1,51 @@
+package io.lbry.browser.reactmodules;
+
+import android.app.Activity;
+import android.content.Context;
+import android.view.WindowManager;
+
+import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.ReactContextBaseJavaModule;
+import com.facebook.react.bridge.ReactMethod;
+
+public class UtilityModule extends ReactContextBaseJavaModule {
+    private Context context;
+
+    public UtilityModule(ReactApplicationContext reactContext) {
+        super(reactContext);
+        this.context = reactContext;
+    }
+
+    @Override
+    public String getName() {
+        return "UtilityModule";
+    }
+
+    @ReactMethod
+    public void keepAwakeOn() {
+      final Activity activity = getCurrentActivity();
+
+      if (activity != null) {
+        activity.runOnUiThread(new Runnable() {
+          @Override
+          public void run() {
+            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+          }
+        });
+      }
+    }
+
+    @ReactMethod
+    public void keepAwakeOff() {
+      final Activity activity = getCurrentActivity();
+
+      if (activity != null) {
+        activity.runOnUiThread(new Runnable() {
+          @Override
+          public void run() {
+            activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+          }
+        });
+      }
+    }
+}