devapp: remove rlh, promote hyangah to mobile primary
devapp: remove rlh, promote hyangah to mobile primary

Change-Id: Ieff6ab6848b27f231c03d9af2e89b30557530303
Reviewed-on: https://go-review.googlesource.com/c/build/+/171701
Reviewed-by: Andrew Bonventre <682ad9f487f614f19e8b7cc5d340bdc8e1c1b128@golang.org>

golang/build,golang/build,golang/build,golang/build