Remove redundant NOTICE symbolic link.

Now that http://aosp/1235427 and http://aosp/1238719 are in, NOTICE
symbolic links are no longer needed.

Bug: 67772237
Bug: 68860345

Test: manually built and diffed before and after system image notices
Change-Id: I932fd2ac6bfdf70b3be858e8eda559ac48df5ff2
diff --git a/NOTICE b/NOTICE
deleted file mode 120000
index 7a694c9..0000000
--- a/NOTICE
+++ /dev/null
@@ -1 +0,0 @@
\ No newline at end of file