Remove redundant NOTICE copied from LICENSE.

Identified using the below shell script:

$ find -H . -name LICENSE -type f -print0 | xargs -0 dirname \
  | while read dir; do \
    if [ -f "${dir}/NOTICE" ] \
        && diff "${dir}/LICENSE" "${dir}/NOTICE" >/dev/null; then \
      echo "${dir}/NOTICE"; \
    fi; \
  done

Now that http://r.android.com/r/1235427 and http://r.android.com/r/1238719 are
merged, LICENSE files copied into NOTICE files are no longer needed.

Bug: 67772237
Bug: 68860345

Test: manually built and diffed before and after system image notices
Change-Id: I8b3377386eabfb67d0cc0ffa62e019adea215668
diff --git a/NOTICE b/NOTICE
deleted file mode 120000
index 7a694c9..0000000
--- a/NOTICE
+++ /dev/null
@@ -1 +0,0 @@
-LICENSE
\ No newline at end of file