Otadexopt: removing bootdevice from /dev/block/bootdevice/by-name/*

We should switch to use /dev/block/by-name/<partition> because there is
no requirement to have a single 'bootdevice' for Android. The symlink is
created in the following change:

  https://android-review.googlesource.com/c/platform/system/core/+/674989

Bug: 80466341
Bug: 78613232
Test: m -j otapreopt_chroot
Test: Successful go/manual_ab_ota on walleye

Change-Id: I26fbf67e72cc2ee93909e95b0254ba1602e6ae8e
Merged-In: I26fbf67e72cc2ee93909e95b0254ba1602e6ae8e