Add config flag to enable new media activity.

app/src/main/java/org/thoughtcrime/securesms/keyvalue/InternalValues.kt

@@ -59,7 +59,18 @@ class InternalValues internal constructor(store: KeyValueStore) : SignalStoreVal
    */
   var forceSinglePane by booleanValue(FORCE_SINGLE_PANE_ON_ALL_DEVICES, false).falseForExternalUsers()
 
-  var useNewMediaActivity by booleanValue(USE_NEW_MEDIA_ACTIVITY, false).falseForExternalUsers()
+  /**
+   * Whether to use the new media-send flow. Internal users can override the remote value.
+   */
+  var useNewMediaActivity: Boolean
+    get() = if (RemoteConfig.internalUser) {
+      getBoolean(USE_NEW_MEDIA_ACTIVITY, RemoteConfig.useNewMediaSendFlow)
+    } else {
+      RemoteConfig.useNewMediaSendFlow
+    }
+    set(value) {
+      putBoolean(USE_NEW_MEDIA_ACTIVITY, value)
+    }
 
   /**
    * Members will not be added directly to a GV2 even if they could be.

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

@@ -1481,5 +1481,14 @@ object RemoteConfig {
     hotSwappable = true
   )
 
+  /** Whether to utilize the new media-send feature module */
+  @JvmStatic
+  @get:JvmName("useNewMediaSendFlow")
+  val useNewMediaSendFlow: Boolean by remoteBoolean(
+    key = "android.useNewMediaSendFlow",
+    defaultValue = false,
+    hotSwappable = true
+  )
+
   // endregion
 }