Make snapuserd recovery_available.

Bug: 349287459
Test: adb reboot recovery
      adb root
      adb shell ls -l /system/bin/snapuserd
(cherry picked from https://android-review.googlesource.com/q/commit:dcc81d427a9cfcb7560b4ba590ace3348b314860)
Merged-In: I69a3f8d2fd2d7dc157d14a0f743650881eec473d
Change-Id: I69a3f8d2fd2d7dc157d14a0f743650881eec473d