Merge changes Icb5ba2a5,Ic5688a2c,I7c42aa37
am: 994929b524

* commit '994929b5244e393e457583c40167d583af16561d':
  Remove android-18/arm symbols not present in platform libc
  Remove LIBC_PRIVATE symbols from android-18 libm
  Remove LIBC_PRIVATE symbols from android-18 libc