To enable sharing of keychain items using access groups in macOS,
the kSecUseDataProtectionKeychain attribute should be set.
This key has effect only in macOS, and is unavailable in iOS 12,
so we set it only in macOS.
Co-authored-by: Davide De Rosa <keeshux@gmail.com>
Better retain access group every time keychain is written to or
read from, there is no good reason to omit it. Requires Keychain
method to be reverted to non-static.
Partially revert 4490f0c116, based
on wrong assumptions about password references.
Roopesh Chander
Davide De Rosa