Delete the reminders system.

app/src/main/java/org/thoughtcrime/securesms/util/RemoteConfig.kt

@@ -1082,15 +1082,6 @@ object RemoteConfig {
     hotSwappable = true
   )
 
-  /** Whether to use the new Banner system instead of the old Reminder system.  */
-  @JvmStatic
-  @get:JvmName("newBannerUi")
-  val newBannerUi: Boolean by remoteBoolean(
-    key = "android.newBannerUi",
-    defaultValue = false,
-    hotSwappable = true
-  )
-
   /** Which phase we're in for the SVR3 migration  */
   val svr3MigrationPhase: Int by remoteInt(
     key = "global.svr3.phase",