Fix ABI version code for fdroid support

Author: Kusoneko

android/app/build.gradle

@@ -94,3 +94,15 @@ flutter {
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
 }
+
+
+ext.abiCodes = ["armeabi-v7a": 1, "arm64-v8a": 2, "x86_64": 4]
+import com.android.build.OutputFile
+android.applicationVariants.all { variant ->
+  variant.outputs.each { output ->
+    def abiVersionCode = project.ext.abiCodes.get(output.getFilter(OutputFile.ABI))
+    if (abiVersionCode != null) {
+      output.versionCodeOverride = variant.versionCode * 10 + abiVersionCode
+    }
+  }
+}