Merge tag 'android-6.0.0_r26' into HEAD

Android 6.0.0 release 26

* tag 'android-6.0.0_r26':
  added 1.4.0-beta5 to prebuilts.
  Add 1.4.0-beta3.

Change-Id: Ieb2fce21abb5d65b11275a58504b673c18f20051