Add default OAUTH_CLIENT_URL_PATH alternative (#7385)

* Add default `OAUTH_CLIENT_URL_PATH` alternative

Previously this was `null`, but we want to use `apps/android` instead to identify Element X Android. Element Pro will use a different value, and other custom apps based on EP will use `null` or their own custom value, if they provided one

* Suppress lint check so the pro app can be built

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

@@ -11,6 +11,8 @@ package io.element.android.libraries.matrix.api.auth
 import io.element.android.libraries.matrix.api.BuildConfig
 
 object OAuthConfig {
+    // This *can* be null if the build time config field is not set
+    @Suppress("UNNECESSARY_SAFE_CALL")
     val CLIENT_URI = BuildConfig.OAUTH_CLIENT_URI_PATH?.let {
         // Concatenate the base URI and the path, ensuring there is exactly one '/' between them
         "${BuildConfig.CLIENT_URI.trimEnd('/')}/${it.trimStart('/')}"