Add DSN in the manual init (#4381)

* Add DSN in the manual init

DSN is an integral part of the manual initialisation

* Update src/platforms/android/configuration/manual-init.mdx

Co-authored-by: Manoel Aranda Neto <5731772+marandaneto@users.noreply.github.com>

* Update src/platforms/android/configuration/manual-init.mdx

Co-authored-by: Manoel Aranda Neto <5731772+marandaneto@users.noreply.github.com>

Co-authored-by: Manoel Aranda Neto <5731772+marandaneto@users.noreply.github.com>

Author: t-h-man

src/platforms/android/configuration/manual-init.mdx

@@ -41,6 +41,7 @@ public class SentryApplication extends Application {
     super.onCreate();
 
     SentryAndroid.init(this, options -> {
+      options.setDsn("___PUBLIC_DSN___");
       // Add a callback that will be used before the event is sent to Sentry.
       // With this callback, you can modify the event or, when returning null, also discard the event.
       options.setBeforeSend((event, hint) -> {
@@ -64,6 +65,7 @@ class SentryApplication : Application() {
     super.onCreate()
 
     SentryAndroid.init(this) { options ->
+      options.dsn = "___PUBLIC_DSN___"
       // Add a callback that will be used before the event is sent to Sentry.
       // With this callback, you can modify the event or, when returning null, also discard the event.
       options.beforeSend =