Remove libchrome dependency from full_update_generator.h am: c485dddb59

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3304095

Change-Id: I5cb74daf3bf0c2e513e6adf024a137d950f05731
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>