test(@angular/build): enable unit-test builder coverage tests #8662

Job	Run time
lint	25s
build	8s
build-e2e-windows	11s
e2e-windows	1s
publish-snapshots	1s
test	1s
Browser Compatibility Tests	1s
e2e-package-managers	1s
e2e-snapshots	1s
e2e	1s
	51s

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