fix(database, Android): resolve limit modifier type casting (#17867)

* fix(database, Android): resolve limit modifier type casting

* test: add tests for limitToFirst and limitToLast stream emissions

Author: SelaseKay

packages/firebase_database/firebase_database/android/src/main/kotlin/io/flutter/plugins/firebase/database/FirebaseDatabasePlugin.kt

@@ -939,11 +939,11 @@ class FirebaseDatabasePlugin :
           "limit" -> {
             when (modifier["name"] as String) {
               "limitToFirst" -> {
-                val value = modifier["limit"] as Int
+                val value = (modifier["limit"] as Number).toInt()
                 query = query.limitToFirst(value)
               }
               "limitToLast" -> {
-                val value = modifier["limit"] as Int
+                val value = (modifier["limit"] as Number).toInt()
                 query = query.limitToLast(value)
               }
             }

tests/integration_test/firebase_database/query_e2e.dart

@@ -226,6 +226,24 @@ void setupQueryTests() {
 
         expect(snapshot.value, isNull);
       });
+
+      test('streams emit limited maps', () async {
+        await ref.set({
+          'a': 'foo',
+          'b': 'bar',
+          'c': 'baz',
+        });
+
+        final event = await ref.orderByKey().limitToFirst(2).onValue.first;
+
+        expect(
+          event.snapshot.value,
+          equals({
+            'a': 'foo',
+            'b': 'bar',
+          }),
+        );
+      });
     });
 
     group('limitToLast', () {
@@ -266,6 +284,24 @@ void setupQueryTests() {
 
         expect(snapshot.value, isNull);
       });
+
+      test('streams emit limited maps', () async {
+        await ref.set({
+          'a': 'foo',
+          'b': 'bar',
+          'c': 'baz',
+        });
+
+        final event = await ref.orderByKey().limitToLast(2).onValue.first;
+
+        expect(
+          event.snapshot.value,
+          equals({
+            'b': 'bar',
+            'c': 'baz',
+          }),
+        );
+      });
     });
 
     group('orderByChild', () {