Add README with details about the status of support for this app am: 44ccf44e93 am: 87e9faef73

Original change: https://android-review.googlesource.com/c/platform/packages/apps/OnDeviceAppPrediction/+/3320574

Change-Id: Ied73a27b922e35b9c92f2ec92b17c33f6d29a788
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

README

diff --git a/README b/README
new file mode 100644
index 0000000..1372f28
--- /dev/null
+++ b/README
@@ -0,0 +1,4 @@
+This app is not actively supported and the source is only available as a
+reference. This project will be removed from the source manifest sometime in the
+future.
+