[workflow] setup ndk

.github/workflows/android.yml

@@ -10,13 +10,18 @@ jobs:
     - uses: actions/upload-artifact@v2
       with:
         path: app/build/outputs/apk/debug/*.apk
-    - name: set up JDK 1.8
+    - name: Setup JDK 1.8
       uses: actions/setup-java@v1
       with:
         java-version: 1.8
+
     - name: Setup Android SDK
       uses: android-actions/setup-android@v2
 
+    - uses: nttld/setup-ndk@v1
+      with:
+        ndk-version: r19c
+
     - name: Build with Gradle
       run: ./gradlew assembleDebug