Add signing and version code.

.gitea/workflows/buildAndroid.yaml

@@ -6,11 +6,27 @@ jobs:
     steps:
       - name: Checkout the code
         uses: actions/checkout@v2
+
       - name: set up JDK
         uses: actions/setup-java@v3
         with:
           java-version: '17'
           distribution: 'temurin'
           cache: gradle
+
+      - name: Prepare signing
+        run: | 
+          touch keystore.properties
+          echo "storePassword=$STOREPASSWORD" >> keystore.properties
+          echo "keyPassword=$KEYPASSWORD" >> keystore.properties
+          echo "keyAlias=key0" >> keystore.properties
+          echo "storeFile=../AndroidKey" >> keystore.properties
+      
+      - name: Generate versionCode
+        run: | 
+          touch version.properties
+          let timestamp=$(date +%s)/10 
+          echo "versionCode=$timestamp" >> version.properties
+
       - name: Build the app
         run: ./gradlew build