Soong writes out text protos for the sbox manifests, and if those change
every time soong changes, we trigger rebuilds of significant portions of
the tree. This is very annoying when attempting to iterate on Soong, so
disable this functionality at the soong_build level.
Bug: 200727888
Change-Id: Icf21e1775a4c4200e983c1b8ac66ddd780d7c90c
66213a64b2