Camera: Add concert mode feature flag

Bug: 297083874
Test: Successful build

Change-Id: Idced29212941fef28bf7d1630982876afc2dd2e9
diff --git a/camera/camera_platform.aconfig b/camera/camera_platform.aconfig
index 5f4faba..3236be4 100644
--- a/camera/camera_platform.aconfig
+++ b/camera/camera_platform.aconfig
@@ -9,6 +9,12 @@
 
 flag {
      namespace: "camera_platform"
+     name: "concert_mode"
+     description: "Introduces a new concert mode camera extension type"
+     bug: "297083874"
+}
+flag {
+     namespace: "camera_platform"
      name: "log_ultrawide_usage"
      description: "Enable measuring how much usage there is for ultrawide-angle cameras"
      bug: "300515796"