Update android build script to support aab file

android/README.ANDROID

@@ -127,18 +127,10 @@ Before compilation you have to set:
 
     export BUILD_TYPE=release
 
+It's also needed to set STK_STOREPASS, STK_KEYSTORE and STK_ALIAS environment
+variables, so that the apk files can be signed.
+
 and then you make standard compilation with:
 
     ./generate_assets.sh
-    ./make.sh -j5
-    
-
-The compiled apk is unsigned, so you have to sign it with your key. To sign it,
-you have to run:
-
-    jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore \
-        my-release-key.keystore SuperTuxKart-release-unsigned.apk alias_name
-        
-and then:
-
-    zipalign -v 4 SuperTuxKart-release-unsigned.apk SuperTuxKart-release.apk
+    ./make.sh -j $(($(nproc) + 1))

android/build.gradle

@@ -28,6 +28,25 @@ android
     compileSdkVersion compile_sdk_version.toInteger()
     buildToolsVersion build_tools_ver
 
+    signingConfigs
+    {
+        release
+        {
+            storeFile file(keystore)
+            storePassword storepass
+            keyAlias alias
+            keyPassword storepass
+        }
+    }
+
+    buildTypes
+    {
+        release
+        {
+            signingConfig signingConfigs.release
+        }
+    }
+
     sourceSets
     {
         main

android/make.sh

@@ -218,6 +218,29 @@ if [ ! -d "$SDK_PATH" ]; then
     exit
 fi
 
+# Check if we have key for signing in release build
+if [ "$GRADLE_BUILD_TYPE" = "assembleRelease" ]; then
+    if [ -z "$STK_KEYSTORE" ]; then
+        echo "Error: STK_KEYSTORE variable is empty."
+        exit
+    fi
+
+    if [ ! -f "$STK_KEYSTORE" ]; then
+        echo "Error: Couldn't find $STK_KEYSTORE file."
+        exit
+    fi
+
+    if [ -z "$STK_STOREPASS" ]; then
+        echo "Error: STK_STOREPASS variable is empty"
+        exit
+    fi
+
+    if [ -z "$STK_ALIAS" ]; then
+        echo "Error: STK_ALIAS variable is empty."
+        exit
+    fi
+fi
+
 # Find newest build-tools version
 if [ -z "$BUILD_TOOLS_VER" ]; then
     BUILD_TOOLS_DIRS=`ls -1 "$SDK_PATH/build-tools" | sort -V -r`
@@ -681,11 +704,17 @@ fi
 export ANDROID_HOME="$SDK_PATH"
 ./gradlew -Pcompile_sdk_version=$COMPILE_SDK_VERSION \
           -Pbuild_tools_ver="$BUILD_TOOLS_VER"       \
+          -Pstorepass="$STK_STOREPASS"               \
+          -Pkeystore="$STK_KEYSTORE"                 \
+          -Palias="$STK_ALIAS"                       \
           $GRADLE_BUILD_TYPE
 
 if [ "$GRADLE_BUILD_TYPE" = "assembleRelease" ]; then
 ./gradlew -Pcompile_sdk_version=$COMPILE_SDK_VERSION \
           -Pbuild_tools_ver="$BUILD_TOOLS_VER"       \
+          -Pstorepass="$STK_STOREPASS"               \
+          -Pkeystore="$STK_KEYSTORE"                 \
+          -Palias="$STK_ALIAS"                       \
           "bundleRelease"
 fi