Add option to print command output and fix env on dumpvars commands

Two fixes:
soong dumpvars commands require TARGET_RELEASE to be set in the env, so
set that.

Added option to print command output which is useful for actually
logging build output not only in the case of command failures.

Test: ABTD run with this change
Bug: 314171817
Change-Id: Ia3ad8ebfa58959c13417abaeeaa42a354c4c61de