Atest: prebuilt update CL 5215534.

The atest prebuilt binary is download from aosp_master
aosp_cf_x86_phone-userdebug 5215534.

Bug:122439807
Bug:122041546

Test: $ source build/envsetup.sh; lunch
      $ rm -f $ANDROID_HOST_OUT/bin/atest
      $ rm -f $ANDROID_BUILD_TOP/out/soong/host/*x86/bin/atest
      $ atest hello_world_test ; echo $?
      $ atest cts hello_world_test VtsCodelabHelloWorldTest RunBluetoothRoboTests --dry-run
      $ atest apex_file_test ; echo $?
      $ cd frameworks/base/services/core/java/com/android/server ; atest

Change-Id: I7634b8c14ee5ef57642acc1fae06746be9bbaa2f