Add informational message to help with updation of VNDK abi references.

Bug: 64267858

Test: create reference dump for libjpeg; add exported function to libjpeg;
      m -j libjpeg.vendor, build fails with helpful message.

Test: create reference dump for libjpeg; add exported function to libjpeg;
      m -j libjpeg.vendor dist DIST_DIR=dist, build fails with helpful message.

Merged-In: Iae25374fe937a0cbe8a8ddf9e23c3bc1f62bbb2a
Change-Id: Iae25374fe937a0cbe8a8ddf9e23c3bc1f62bbb2a
(cherry picked from commit d8b70a39)
(cherry picked from commit 301aa8a8dcb0a92e96ffbf1aa2da3ca49ce2bda9)