Test building example app on CI

.github/workflows/ci.yml

+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  install-deps:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Use Node.js 12.x
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+      - name: Install yarn
+        run: npm install -g yarn
+      - name: Install dependencies
+        run: yarn install
+  js-tests:
+    runs-on: ubuntu-latest
+    needs: install-deps
+    steps:
+      - name: Run tests
+        run: yarn test
+  android-build:
+    runs-on: ubuntu-latest
+    needs: install-deps
+    steps:
+      - name: Build android example app
+        run: cd example/app && ./gradlew assembleRelease

.github/workflows/nodejs.yml

-name: Node CI
-
-on: [push, pull_request]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v1
-      - name: Use Node.js 10.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 10.x
-      - name: Install yarn
-        run: npm install -g yarn
-      - name: Install dependencies
-        run: yarn install
-      - name: Run tests
-        run: yarn test

example/android/app/build.gradle

  */
 
 project.ext.react = [
-    entryFile: "index.js",
+    entryFile: "example/index.js",
     enableHermes: false,  // clean and rebuild if changing
 ]