Add a domain for derive_sdk which is allowed to set
persist.com.android.sdkext.sdk_info, readable by all
apps (but should only be read by the BCP).
Bug: 137191822
Test: run derive_sdk, getprop persist.com.android.sdkext.sdk_info
Change-Id: I389116f45faad11fa5baa8d617dda30fb9acec7a