refactor(android): move sample app under examples/sample-app/

Rename the gradle sample project from :sdk-android-sample to :sample-app
so the isolated example for users lives beside its spec in examples/.

examples/sample-app/android/build.gradle.kts

@@ -0,0 +1,36 @@
+plugins {
+    id("com.android.application") version "8.11.0"
+    kotlin("android") version "2.1.21"
+}
+
+android {
+    namespace = "dev.uatu.sample"
+    compileSdk = 35
+
+    defaultConfig {
+        applicationId = "dev.uatu.sample"
+        minSdk = 24
+        targetSdk = 35
+        versionCode = 1
+        versionName = findProperty("uatu.version") as String? ?: "0.0.0-dev"
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = "17"
+    }
+
+    buildTypes {
+        debug {
+            isDebuggable = true
+        }
+    }
+}
+
+dependencies {
+    implementation(project(":sdk-android"))
+}