Merge changes If317bf19,Ie8b5bc0e,Iaa8c88aa,Idab7680c am: f3cbb4c77d
am: db5fd7d438

* commit 'db5fd7d438296a4fedcdc851125779bb430d57f2':
  Remove symbols that are not present in platform libc
  Remove LIBC_PRIVATE symbols from android-21 libdl
  Remove LIBC_PRIVATE symbols from android-21 libm
  Remove LIBC_PRIVATE symbols from android-21 libc