ANDROID: README.md: document FROMLIST not being allowed for rejected changes

Recently, multiple patch series have been submitted to Android kernels
with the FROMLIST: tag, despite them containing changes that have been
rejected by the upstream community, sometimes many years ago.

FROMLIST is to be used for things that have a chance to be accepted
upstream, or for work-in-progress changes, NOT for rejected submissions,
as using this tag should not hide this rejection state.

Bug: 391973735
Change-Id: I2e73d43dd780c01e9cfd6d1f249c1c9eebcf1a3d
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

README.md

@@ -128,6 +128,12 @@ a maintainer tree)
         Signed-off-by: Joe Smith <joe.smith@foo.org>
 ```
 
+- If a patch has been submitted to the community, but rejected, do NOT use the
+  `FROMLIST:` tag to try to hide this fact.  Use the `ANDROID:` tag as
+  described below as this must be considered as an Android-specific submission,
+  not an upstream submission as the community will not accept these changes
+  as-is.
+
 ## Requirements for Android-specific patches: `ANDROID:`
 
 - If the patch is fixing a bug to Android-specific code