In general, it appears that libselinux and libsepol interpret paths and
contexts as bytes. For instance, selabel_file(5) mentions about the path
field of file_contexts:
Strings representing paths are processed as bytes (as opposed to
Unicode), meaning that non-ASCII characters are not matched
by a single wildcard.
libsepol also uses primitives such as strchr[1], which explicitly
operate at the byte level (see strchr(3)). However, practically, Android
paths and contexts all uses ASCII characters.
Use the str type (i.e., Unicode) for all Python code to avoid a larger
refactoring. Ensure we convert to bytes for inputs and outputs of
libsepolwrap.so. The encoding "ascii" is used, which will raise an error
should a context or type contain non-ASCII characters.
Update headers to match development/docs/copyright-templates.
[1] https://cs.android.com/android/platform/superproject/+/master:external/selinux/libsepol/src/context_record.c;l=224;drc=454466e2e49fd99f36db78396e604962b8682cb4
Bug: 200119288
Test: lunch aosp_bramble-userdebug && m
Test: atest --host fc_sort_test
Test: manually run searchpolicy
Change-Id: I72d41a35f90b2d4112e481cd8d7408764a6c8132
