More moving shell functions in envsetup.sh to standalone scripts. am: 3acb308f

Original change: https://android-review.googlesource.com/c/platform/build/+/3103321



Change-Id: Ib366837c4912edf61f13adfdda0c84667048d404
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>