chore: e2e Android sample - move keys and url into config

e2e/android/app/build.gradle.kts

@@ -1,10 +1,19 @@
+import java.util.Properties
+
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.android)
     alias(libs.plugins.kotlin.compose)
     id("net.bytebuddy.byte-buddy-gradle-plugin") version "1.17.6"
 }
 
+val localProperties = Properties().apply {
+    val localPropertiesFile = rootProject.file("local.properties")
+    if (localPropertiesFile.exists()) {
+        localPropertiesFile.inputStream().use { load(it) }
+    }
+}
+
 android {
     namespace = "com.example.androidobservability"
     compileSdk = 36
@@ -16,6 +25,22 @@ android {
         versionName = "1.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+
+        buildConfigField(
+            "String",
+            "LAUNCHDARKLY_MOBILE_KEY",
+            "\"${localProperties.getProperty("launchdarkly.mobileKey", "")}\""
+        )
+        buildConfigField(
+            "String",
+            "OTLP_ENDPOINT",
+            "\"${localProperties.getProperty("launchdarkly.otlpEndpoint", "").ifEmpty { "https://otel.observability.app.launchdarkly.com:4318" }}\""
+        )
+        buildConfigField(
+            "String",
+            "BACKEND_URL",
+            "\"${localProperties.getProperty("launchdarkly.backendUrl", "").ifEmpty { "https://pub.observability.app.launchdarkly.com" }}\""
+        )
     }
 
     buildTypes {
@@ -36,6 +61,7 @@ android {
     }
     buildFeatures {
         compose = true
+        buildConfig = true
     }
     packaging {
         resources {

e2e/android/app/src/main/java/com/example/androidobservability/BaseApplication.kt

@@ -1,6 +1,7 @@
 package com.example.androidobservability
 
 import android.app.Application
+import android.util.Log
 import android.widget.ImageView
 import com.launchdarkly.observability.api.ObservabilityOptions
 import com.launchdarkly.observability.client.TelemetryInspector
@@ -18,20 +19,21 @@ import com.launchdarkly.sdk.android.LDConfig
 import io.opentelemetry.api.common.AttributeKey
 import io.opentelemetry.api.common.Attributes
 import com.launchdarkly.observability.sdk.LDReplay
+import com.launchdarkly.sdk.android.FeatureFlagChangeListener
 
 open class BaseApplication : Application() {
 
     companion object {
-        // TODO O11Y-376: Update this credential to be driven by env variable or gradle property
-        // Set LAUNCHDARKLY_MOBILE_KEY to your LaunchDarkly SDK mobile key.
-        const val LAUNCHDARKLY_MOBILE_KEY = "MOBILE_KEY_GOES_HERE"
+        const val LAUNCHDARKLY_MOBILE_KEY = BuildConfig.LAUNCHDARKLY_MOBILE_KEY
     }
 
     var observabilityOptions = ObservabilityOptions(
         resourceAttributes = Attributes.of(
             AttributeKey.stringKey("example"), "value"
         ),
         debug = true,
+        otlpEndpoint = BuildConfig.OTLP_ENDPOINT,
+        backendUrl = BuildConfig.BACKEND_URL,
         tracesApi = ObservabilityOptions.TracesApi.enabled(),
         metricsApi = ObservabilityOptions.MetricsApi.enabled(),
         instrumentations = ObservabilityOptions.Instrumentations(
@@ -89,9 +91,22 @@ open class BaseApplication : Application() {
         LDClient.init(this@BaseApplication, ldConfig, context)
         telemetryInspector = observabilityPlugin.getTelemetryInspector()
 
+        flagEvaluation()
+
         LDReplay.start()
     }
 
+    fun flagEvaluation() {
+        val flagKey = "feature1"
+        val value = LDClient.get().boolVariation(flagKey, false)
+        Log.i("flag", "sync ${flagKey} value= ${value}")
+        val listener = FeatureFlagChangeListener {
+            val newValue = LDClient.get().boolVariation(flagKey, false)
+            Log.i("flag", "listened ${flagKey} value= ${newValue}")
+        }
+        LDClient.get().registerFeatureFlagListener(flagKey, listener)
+    }
+
     override fun onCreate() {
         super.onCreate()
         realInit()