Wire AndroidX SplashScreen for the XML sample HostActivity

Add a dedicated Theme.App.Splash extending Theme.SplashScreen so the new
brand splash works on every supported API level (minSdk = 21) instead of
only API 31+. Background uses ic_launcher_background and the animated icon
points at the launcher mipmap; postSplashScreenTheme hands control back to
AppTheme once the splash dismisses. HostActivity calls installSplashScreen()
before super.onCreate().

Mirrors the wiring already in place for the Compose sample so both samples
share the same splash treatment for the upcoming Lottie animation.

Author: andremion

stream-chat-android-ui-components-sample/build.gradle.kts

@@ -152,6 +152,7 @@ dependencies {
     implementation(libs.androidx.activity.ktx)
     implementation(libs.androidx.appcompat)
     implementation(libs.androidx.core.ktx)
+    implementation(libs.androidx.core.splashscreen)
     implementation(libs.androidx.lifecycle.livedata.ktx)
     implementation(libs.androidx.preference)
     implementation(libs.androidx.constraintlayout)

stream-chat-android-ui-components-sample/src/main/AndroidManifest.xml

@@ -50,6 +50,7 @@
         <activity
             android:name="io.getstream.chat.ui.sample.feature.HostActivity"
             android:exported="true"
+            android:theme="@style/Theme.App.Splash"
             android:windowSoftInputMode="adjustResize"
             >
             <intent-filter>

stream-chat-android-ui-components-sample/src/main/kotlin/io/getstream/chat/ui/sample/feature/HostActivity.kt

@@ -21,6 +21,7 @@ import android.content.Intent
 import android.os.Bundle
 import android.view.View
 import androidx.appcompat.app.AppCompatActivity
+import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.updatePadding
@@ -34,6 +35,7 @@ const val EXTRA_PARENT_MESSAGE_ID = "extra_parent_message_id"
 class HostActivity : AppCompatActivity(R.layout.activity_main) {
 
     override fun onCreate(savedInstanceState: Bundle?) {
+        installSplashScreen()
         super.onCreate(savedInstanceState)
         setupEdgeToEdge()
         if (savedInstanceState != null && lastNonConfigurationInstance == null) {

stream-chat-android-ui-components-sample/src/main/res/values/themes.xml

@@ -33,4 +33,10 @@
     <style name="AudioRecordPlayerViewTheme" parent="StreamUi.AudioRecordPlayerView">
         <item name="streamUiAudioRecordPlayerFileIconContainerVisible">false</item>
     </style>
+
+    <style name="Theme.App.Splash" parent="Theme.SplashScreen">
+        <item name="windowSplashScreenBackground">@color/ic_launcher_background</item>
+        <item name="windowSplashScreenAnimatedIcon">@mipmap/ic_launcher_foreground</item>
+        <item name="postSplashScreenTheme">@style/AppTheme</item>
+    </style>
 </resources>