[PATCH flutter-frontend v3 3/3] fix #4281: android: register OpenID Connect callback activity

[Azharul Haque <haque@azharul.com>]

proxmox_login_manager's OpenID login flow (see the corresponding
patch there) opens the provider's authorization URL via
flutter_web_auth_2 and expects the provider's redirect back to
com.proxmox.app://openid-callback to be captured by the app. On
Android this requires explicitly registering flutter_web_auth_2's
CallbackActivity for that scheme; add it, following the plugin's setup
instructions.

No changes needed on iOS: ASWebAuthenticationSession handles the
custom-scheme redirect without any Info.plist registration.

Signed-off-by: Azharul Haque <haque@azharul.com>
---
 android/app/src/main/AndroidManifest.xml | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index 654f13d..658f916 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -24,6 +24,21 @@
             </intent-filter>
         </activity>
 
+        <!-- Captures the OpenID Connect provider's redirect back into the app
+             for realms configured with an OAuth/OIDC login, see
+             flutter_web_auth_2 and ProxmoxLoginForm's OpenID login flow. -->
+        <activity
+            android:name="com.linusu.flutter_web_auth_2.CallbackActivity"
+            android:exported="true"
+            android:taskAffinity="">
+            <intent-filter android:label="flutter_web_auth_2">
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="com.proxmox.app" />
+            </intent-filter>
+        </activity>
+
         <!-- This is used by Flutter to generate GeneratedPluginRegistrant.java -->
         <meta-data
             android:name="flutterEmbedding"
-- 
2.50.1 (Apple Git-155)