refactor(code_push_client)!: use new channels endpoint (#863)

packages/shorebird_code_push_client/lib/src/code_push_client.dart

@@ -253,8 +253,8 @@ class CodePushClient {
     required String channel,
   }) async {
     final response = await _httpClient.post(
-      Uri.parse('$_v1/channels'),
-      body: json.encode({'app_id': appId, 'channel': channel}),
+      Uri.parse('$_v1/apps/$appId/channels'),
+      body: json.encode({'channel': channel}),
     );
 
     if (response.statusCode != HttpStatus.ok) {
@@ -401,9 +401,7 @@ class CodePushClient {
   /// List all channels for the provided [appId].
   Future<List<Channel>> getChannels({required String appId}) async {
     final response = await _httpClient.get(
-      Uri.parse('$_v1/channels').replace(
-        queryParameters: {'appId': appId},
-      ),
+      Uri.parse('$_v1/apps/$appId/channels'),
     );
 
     if (response.statusCode != HttpStatus.ok) {

packages/shorebird_code_push_client/test/src/code_push_client_test.dart

@@ -510,8 +510,10 @@ void main() {
             .captured
             .single as http.BaseRequest;
         expect(request.method, equals('POST'));
-        expect(request.url,
-            equals(v1('apps/$appId/releases/$releaseId/artifacts')));
+        expect(
+          request.url,
+          equals(v1('apps/$appId/releases/$releaseId/artifacts')),
+        );
         expect(request.hasStandardHeaders, isTrue);
       });
 
@@ -849,7 +851,7 @@ void main() {
             .captured
             .single as http.BaseRequest;
         expect(request.method, equals('POST'));
-        expect(request.url, equals(v1('channels')));
+        expect(request.url, equals(v1('apps/$appId/channels')));
         expect(request.hasStandardHeaders, isTrue);
       });
 
@@ -926,7 +928,9 @@ void main() {
 
         expect(
           request.url,
-          codePushClient.hostedUri.replace(path: '/api/v1/channels'),
+          codePushClient.hostedUri.replace(
+            path: '/api/v1/apps/$appId/channels',
+          ),
         );
       });
     });
@@ -1590,7 +1594,7 @@ void main() {
             .captured
             .single as http.BaseRequest;
         expect(request.method, equals('GET'));
-        expect(request.url, equals(v1('channels?appId=$appId')));
+        expect(request.url, equals(v1('apps/$appId/channels')));
         expect(request.hasStandardHeaders, isTrue);
       });