This commit adds a new GitHub Actions workflow to automatically build the Android APK for the frontend application.

The workflow is triggered on push to the main branch and can also be run manually. It performs the following steps:
- Sets up the Node.js and Java environment.
- Installs project dependencies.
- Builds the Android APK using Expo Application Services (EAS).
- Uploads the generated APK as a build artifact.

An `eas.json` configuration file has also been added to the frontend project.

Author: google-labs-jules[bot]

.github/workflows/android-build.yml

@@ -0,0 +1,46 @@
+name: Build Android APK
+
+on:
+  push:
+    branches: [ "main" ]
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    env:
+      EXPO_TOKEN: ${{ secrets.EXPO_TOKEN }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: 18
+
+      - name: Set up Java
+        uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+
+      - name: Install Expo CLI
+        run: npm install -g eas-cli
+
+      - name: Install dependencies
+        run: npm install
+        working-directory: ./frontend
+
+      - name: Build and Download APK
+        run: |
+          URL=$(eas build --platform android --profile production --non-interactive --wait --output=./app.apk)
+          echo "APK URL: $URL"
+        working-directory: ./frontend
+
+      - name: Upload APK
+        uses: actions/upload-artifact@v3
+        with:
+          name: app
+          path: frontend/app.apk

frontend/eas.json

@@ -0,0 +1,18 @@
+{
+  "cli": {
+    "version": ">= 7.6.0"
+  },
+  "build": {
+    "development": {
+      "developmentClient": true,
+      "distribution": "internal"
+    },
+    "preview": {
+      "distribution": "internal"
+    },
+    "production": {}
+  },
+  "submit": {
+    "production": {}
+  }
+}