ci: add assemble workflow

.github/workflows/android.yml

@@ -0,0 +1,24 @@
+name: 'Assemble samples'
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    name: ${{ github.event.pull_request.title || github.event.head_commit.message }}
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: set up JDK
+      uses: actions/setup-java@v4
+      with:
+        java-version: '17'
+        distribution: 'temurin'
+        cache: gradle
+    - name: Build with Gradle
+      run: ./gradlew assembleDebug

.github/workflows/ci.yml → .github/workflows/spotless.yml

@@ -1,4 +1,4 @@
-name: CI
+name: 'Spotless check'
 
 on:
   schedule:

README.md

@@ -1,6 +1,6 @@
 # Naver Ad Manager SDK for Android
 
-![Maven Central](https://img.shields.io/maven-central/v/com.naver.gfpsdk/nam-core)
+![Maven Central](https://img.shields.io/maven-central/v/com.naver.gfpsdk/nam-core) ![latest build](https://github.com/naver/nam-sdk-android/actions/workflows/android.yml/badge.svg)
 
 Integrating the `Naver Ad Manager(NAM) SDK` into an app is the first step toward displaying ads and earning revenue. Once you've integrated the SDK,
 you can choose an ad format (such as banner or native or rewarded or interstitial) and follow the steps to implement it.