Update is_valid_package_name() to match framework.

The framework has a new format for /data/app directory names in OC
to protect user privacy.  This change updates the validation logic
in installd to support the new format.

For consistency the logic now mirrors the package name validation
logic used by PackageParser.

Test: /data/nativetest64/installd_utils_test/installd_utils_test
Bug: 33705143
Change-Id: I41d270942479c52e063c29a2cb9552d7b238b86e