releasetools: Capture and dump stdout/stderr outputs on errors.

For the functions in common.py, capture the stdout/stderr outputs when
shelling out to external tools. Dump the outputs on errors.

Bug: 76123422
Test: Inject errors to signapk.jar / brotli / unzip. Check the outputs.
Change-Id: Ib2d4272528b83a50bb727788cf8a5211e2ddade8