Remove sdk_version: "none" restriction

Not entirely sure what the history behind requiring only libcore
projects use this, but it is a bit annoying to have to allow-list every
use.

Bug: 173606718
Test: m nothing
Merged-In: I66f71e67d3f17e7f983c8537dff537fe8419da95
Change-Id: I66f71e67d3f17e7f983c8537dff537fe8419da95
(cherry picked from commit 0af20eff)