ci: configure Gradle to sign release APKs directly within the build workflow

Author: kevinlee-06

.github/workflows/release.yml

@@ -39,23 +39,21 @@ jobs:
             echo "version=${{ github.ref_name }}" >> $GITHUB_OUTPUT
           fi
 
-      - name: Build Unsigned Release APK
-        run: ./gradlew assembleRelease
+      - name: Decode Keystore
+        run: |
+          echo "${{ secrets.SIGNING_KEY_STORE_BASE64 }}" | base64 --decode > release.keystore
 
-      - name: Sign APK
-        uses: r0adkll/sign-android-release@v1
-        id: sign_app
-        with:
-          releaseDirectory: app/build/outputs/apk/release
-          signingKeyBase64: ${{ secrets.SIGNING_KEY_STORE_BASE64 }}
-          alias: ${{ secrets.SIGNING_KEY_ALIAS }}
-          keyStorePassword: ${{ secrets.SIGNING_STORE_PASSWORD }}
-          keyPassword: ${{ secrets.SIGNING_KEY_PASSWORD }}
-          buildToolsVersion: 35.0.0
+      - name: Build and Sign Release APK
+        env:
+          KEYSTORE_FILE: ${{ github.workspace }}/release.keystore
+          KEYSTORE_PASSWORD: ${{ secrets.SIGNING_STORE_PASSWORD }}
+          KEY_ALIAS: ${{ secrets.SIGNING_KEY_ALIAS }}
+          KEY_PASSWORD: ${{ secrets.SIGNING_KEY_PASSWORD }}
+        run: ./gradlew assembleRelease
 
       - name: Rename Signed APK
         run: |
-          mv ${{steps.sign_app.outputs.signedReleaseFile}} \
+          mv app/build/outputs/apk/release/app-release.apk \
              app/build/outputs/apk/release/adbkit-${{ steps.vars.outputs.version }}.apk
 
       - name: Create Release

app/build.gradle.kts

@@ -20,6 +20,17 @@ android {
         release {
             isMinifyEnabled = true
             isShrinkResources = true
+            
+            val keystoreFile = System.getenv("KEYSTORE_FILE")
+            if (keystoreFile != null) {
+                signingConfig = signingConfigs.create("release") {
+                    storeFile = file(keystoreFile)
+                    storePassword = System.getenv("KEYSTORE_PASSWORD")
+                    keyAlias = System.getenv("KEY_ALIAS")
+                    keyPassword = System.getenv("KEY_PASSWORD")
+                }
+            }
+            
             proguardFiles(
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"