Make rros not overridable

There are no current users of overriding rros, so it's dead code.
Additionally, there is some evidence of accidental misuse, so remove it
for now as we don't want arbitrary properties of AOSP modules to be
overridable in the general case.

Bug: 270542561
Bug: 269568074
Test: presubmit
Change-Id: I030abd644358baefc0d1543649c8a2a81a7491d0