Convert `clean-oat rules` to Android.bp

Since Soong genrules now run in sandboxed mode, they cannot execute
commands like `rm -rf` within `clean-oat-target` to remove physical
directories.

The only solution is to move the `clean-oat-target` commands into
`build/core/tasks`.

Bug: 345133095
Test: m clean-oat; m clean-oat-host
Change-Id: I31808e47590540c9ed83362216428f3cf1609d59
1 file changed