git: openjdk/jdk-sandbox: jep486: Change "SecurityManager" to "Security Manager". Add some missing code and linkplain tags.

[duke]

Changeset: 275dabd4
Branch: jep486
Author:    Sean Mullan <sean.mullan at oracle.com>
Date:      2024-10-26 15:52:36 +0000
URL:       https://git.openjdk.org/jdk-sandbox/commit/275dabd4dbc8f443901dc5d82b281111dcbf15e6

Change "SecurityManager" to "Security Manager". Add some missing code and linkplain tags.

! src/java.base/share/classes/java/security/AccessControlContext.java
! src/java.base/share/classes/java/security/AccessController.java
! src/java.base/share/classes/java/security/DomainCombiner.java