Revert "adbd: lessen security constraints when the device is unlocked"

This reverts commit f1d3dbc3.

With the following changes to move /sbin/adbd to /system/bin/adbd,
we don't need this workaround anymore.

  https://android-review.googlesource.com/#/q/topic:move-adbd-to-system+(status:open+OR+status:merged)

Bug: 63313955
Bug: 63381692
Bug: 64822208
Test: 'adb root' works in VTS for a non-A/B device (userdebug GSI + user boot.img)

Change-Id: Ic1249d6abd7d6e6e7380a661df16d25447853a48