Phone App: rename Android package to com.drivervault.phoneapp

Updates the Gradle namespace/applicationId, moves MainActivity.kt to the
matching source directory, and refreshes the package id in the README.

The Dart package name in pubspec.yaml is unchanged. Since the application
id changed, existing installs will not upgrade in place and their local
secure-storage/prefs data does not carry over.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Phone App/android/app/build.gradle.kts

@@ -5,7 +5,7 @@ plugins {
 }
 
 android {
-    namespace = "com.carcontrole.carcontrol_phone"
+    namespace = "com.drivervault.phoneapp"
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 
@@ -15,8 +15,7 @@ android {
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
-        applicationId = "com.carcontrole.carcontrol_phone"
+        applicationId = "com.drivervault.phoneapp"
         // You can update the following values to match your application needs.
         // For more information, see: https://flutter.dev/to/review-gradle-config.
         minSdk = flutter.minSdkVersion

Phone App/android/app/src/main/kotlin/com/drivervault/phoneapp/MainActivity.kt

@@ -1,4 +1,4 @@
-package com.carcontrole.carcontrol_phone
+package com.drivervault.phoneapp
 
 import io.flutter.embedding.android.FlutterFragmentActivity