feat: show notification and battery optimization warning

mobile/pigeon/permission_api.dart

@@ -0,0 +1,17 @@
+import 'package:pigeon/pigeon.dart';
+
+enum PermissionStatus { granted, denied, permanentlyDenied }
+
+@ConfigurePigeon(
+  PigeonOptions(
+    dartOut: 'lib/platform/permission_api.g.dart',
+    kotlinOut: 'android/app/src/main/kotlin/app/alextran/immich/permission/PermissionApi.g.kt',
+    kotlinOptions: KotlinOptions(package: 'app.alextran.immich.permission'),
+    dartOptions: DartOptions(),
+    dartPackageName: 'immich_mobile',
+  ),
+)
+@HostApi()
+abstract class PermissionApi {
+  PermissionStatus isIgnoringBatteryOptimizations();
+}