recovery: Fix the flickering when turning on text mode.

When there's no command specified when booting into debuggable builds
(such as using `adb reboot recovery`), we turn on the text mode (i.e.
recovery menu) directly. This CL fixes the issue to avoid showing the
background image in a flash while turning on the text mode.

Bug: 63985334
Test: `fastboot boot $OUT/recovery.img` and it shows the recovery menu
      directly without the no command image in a flash.
Change-Id: Id86bbe346ab76c8defc95e2b423e695a86774b09