Move to Flutter 3.47, use the improvements that come with this (#64)

Reviewed-on: #64

android/app/build.gradle.kts

@@ -0,0 +1,74 @@
+import java.util.Properties
+
+plugins {
+    id("com.android.application")
+    id("dev.flutter.flutter-gradle-plugin")
+}
+
+val keystoreProperties = Properties()
+val keystorePropertiesFile = rootProject.file("key.properties")
+
+if (keystorePropertiesFile.exists()) {
+    keystorePropertiesFile.inputStream().use {
+        keystoreProperties.load(it)
+    }
+}
+
+android {
+    namespace = "nexus.federated.nexus"
+    compileSdk = 36
+    ndkVersion = flutter.ndkVersion
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    defaultConfig {
+        applicationId = "nexus.federated.nexus"
+        minSdk = 29
+        targetSdk = flutter.targetSdkVersion
+        versionCode = flutter.versionCode
+        versionName = flutter.versionName
+    }
+
+    signingConfigs {
+        create("release") {
+            keyAlias = "key"
+
+            val storePath =
+                keystoreProperties["path"]?.toString()
+                    ?: System.getenv("KEYSTORE_PATH")
+
+            storeFile = storePath?.let { file(it) }
+
+            keyPassword =
+                keystoreProperties["password"]?.toString()
+                    ?: System.getenv("KEYSTORE_PASSWORD")
+
+            storePassword =
+                keystoreProperties["password"]?.toString()
+                    ?: System.getenv("KEYSTORE_PASSWORD")
+        }
+    }
+
+    buildTypes {
+        release {
+            signingConfig = signingConfigs.getByName("release")
+        }
+
+        debug {
+            applicationIdSuffix = ".debug"
+        }
+    }
+}
+
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
+    }
+}
+
+flutter {
+    source = "../.."
+}