crunch_flags: keep-sorted lines are not descriptions

Also fix a typo in parsing declare-release-config.

Bug: 328495189
Test: manual, TH
Ignore-AOSP-First: cherry-pick
Merged-In: Ibfed4a217275df0dd6bd9c2fb124e0d1f791be08
Change-Id: Ibfed4a217275df0dd6bd9c2fb124e0d1f791be08