chore: fix boolean comparison

[parthea]

Fixes warning from flake8 . --select E712

(py39) partheniou@partheniou-vm-2:~/git/google-api-python-client$ flake8 . --select E712
./scripts/buildprbody.py:83:40: E712 comparison to False should be 'if cond is False:' or 'if not cond:'
./scripts/changesummary.py:211:46: E712 comparison to True should be 'if cond is True:' or 'if cond:'
./scripts/changesummary.py:223:50: E712 comparison to True should be 'if cond is True:' or 'if cond:'