So that we can more easily enable these new flags on several
modules.
It seems you can still apply a python_defaults to a python_library
even with this change, so I didn't break it out into a separate
python_binary_defaults.
Bug: 245583294
Test: m py_dont_import_folder_of_entrypoint_test && out/host/linux-x86/testcases/py_dont_import_folder_of_entrypoint_test/x86_64/py_dont_import_folder_of_entrypoint_test
Change-Id: Iecf9c1845df4630bafdea9957eb2450c15f8596b
Add an empty DepsMutator to ModuleBase so it doesn't have to be
implemented on every module that doesn't need it.
Test: all soong tests
Change-Id: I545a832a0dbf27386d3080377a75ea482cd9ce59
