Camera: Add AE priority mode tags

- Add AE priority mode tags
- Populate CONTROL_AE_AVAILABLE_PRIORITY_MODES with at
least OFF mode

Test: Camera CTS with and without flag
Bug: 359944765
Flag: com.android.internal.camera.flags.ae_priority

Change-Id: I1aec82f212915d6ddbd0e6f55b015a0d840b2585
diff --git a/camera/camera_platform.aconfig b/camera/camera_platform.aconfig
index 774d21c..55e5fc8 100644
--- a/camera/camera_platform.aconfig
+++ b/camera/camera_platform.aconfig
@@ -226,3 +226,12 @@
     description: "Gives apps explicit control on reflects zoom via ZOOM_RATIO capture result"
     bug: "298899993"
 }
+
+flag {
+    namespace: "camera_platform"
+    is_exported: true
+    name: "ae_priority"
+    description: "Add AE priority modes"
+    bug: "359944765"
+}
+