gsi_util: refactors Checker and VintfChecker
This change includes several refactoring:
1. Adds more function/class comments.
2. Renames the fields in namedtuples 'CheckListItem' and 'CheckResultItem'.
3. Fixes the vintf check issue. It should do two checks:
system -> vendor and vendor -> system, instead of one direction.
4. Fixes import statements, should only import module or package name.
5. Use python3-style print() function instead of print statement.
6. Fix the missing 'import errno' in image_mounter.
7. Checks *.py under 'checker' folder can pass 'pylint'.
Disables the check for a given line if it cannot pass.
e.g., pylint: disable=too-few-public-methods
8. Changes 'summary' result from a string 'pass' to '#pass/#total'.
Bug: 70253825
Test: m gsi_util
Test: gsi_util --debug check_compat --system $OUT/system.img --vendor adb
Test: gsi_util --debug check_compat --system $OUT/system.img --vendor $OUT/vendor.img
Test: gsi_util check_compat --only-summary --system $OUT/system --vendor $OUT/vendor
Test: gsi_util --debug check_compat --system adb --vendor adb vintf
Change-Id: Ia08d1fbeee62f62667876b54778489c89e4228a1
6 files changed