keystore2: rename the ScreenLockBound superencryption keys and type

Rename the ScreenLockBound superencryption keys and superencryption type
to UnlockedDeviceRequired.  This avoids confusion about what "screen
lock bound" means and makes the terminology consistent with the
UnlockedDeviceRequired key parameter in the API.

Bug: 296464083
Test: atest -p --include-subdirs system/security/keystore2
Test: atest CtsKeystoreTestCases
Flag: exempt, mechanical refactoring and comment changes
Change-Id: I98f7716d05c06f8c6db0f3eb616fb6e780407c2d
diff --git a/keystore2/src/enforcements.rs b/keystore2/src/enforcements.rs
index 61ec006..bb23b82 100644
--- a/keystore2/src/enforcements.rs
+++ b/keystore2/src/enforcements.rs
@@ -774,7 +774,7 @@
                     Candidate { priority: 3, enc_type: SuperEncryptionType::BootLevel(*level) }
                 }
                 KeyParameterValue::UnlockedDeviceRequired if *domain == Domain::APP => {
-                    Candidate { priority: 2, enc_type: SuperEncryptionType::ScreenLockBound }
+                    Candidate { priority: 2, enc_type: SuperEncryptionType::UnlockedDeviceRequired }
                 }
                 KeyParameterValue::UserSecureID(_) if *domain == Domain::APP => {
                     Candidate { priority: 1, enc_type: SuperEncryptionType::AfterFirstUnlock }