These files are not needed once the size has been calculated and there
is no point in keeping them around.
Deleting them prevents, for example, uploading unnecessary files from
`aio/dist/` to Firebase (because `deploy-to-firebase.sh` runs the
payload size checks right before deploying).
PR Close#26746
The scripts were accidentally broken in #20524. More specifically, when a limit
was exceeded the script would break while trying to log an error message due to
a missing `commit` variable.
This commit fixes it and also does some minor clean-up (improve docs, use more
descriptive variable names, remove dead code, etc).
PR Close#20683
George Kalpakas
Igor Minar
Yuan Gao
Misko Hevery