Adapt build_chd_utils.py for use with Python versions below 3.10.

Parenthesized Context Manager was introduced in Python 3.10,
so we shouldn't use it in the CHD build script.

Bug: 331139805
Test: build_cf_hybrid_device
Change-Id: Ib2b5296405eab201fccb69f82af5bbb3825650db
1 file changed