Improve the callback uri format and customization. (#4664)

* Remove unused SUPPORT_EMAIL_ADDRESS

* Improve the callback uri format and customization.

Use io.element.android for the scheme of Oidc redirection for Element X.
For nightly the scheme will be io.element.android.nightly
For debug the scheme will be  io.element.android.debug

Element Pro is using `io.element`

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/auth/OidcConfig.kt

@@ -12,11 +12,6 @@ import io.element.android.libraries.matrix.api.BuildConfig
 object OidcConfig {
     const val CLIENT_URI = BuildConfig.CLIENT_URI
 
-    // Notes:
-    // 1. the scheme must match the value declared in the AndroidManifest.xml
-    // 2. the scheme must be the reverse of the host of CLIENT_URI
-    const val REDIRECT_URI = BuildConfig.REDIRECT_URI
-
     // Note: host must match with the host of CLIENT_URI
     const val LOGO_URI = BuildConfig.LOGO_URI
 

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/auth/OidcRedirectUrlProvider.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.matrix.api.auth
+
+interface OidcRedirectUrlProvider {
+    fun provide(): String
+}