Add PrivacySandboxSdkLibraryPlugin

New Androidx Gradle Plugin that provides assistance for Android
libraries consumed by privacy sandbox sdk modules. The plugin configures
the tools-apipackager as a KSP symbol processor and adds necessary
dependencies.

Bug: 244407607
Test: PrivacySandboxSdkLibraryPluginTest
Change-Id: I9beae1d6c94ae42473b844277bdc94af476ff5c2
diff --git a/settings.gradle b/settings.gradle
index 58e74d7..8117fa8 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -814,6 +814,7 @@
 includeProject(":print:print", [BuildType.MAIN])
 includeProject(":privacysandbox:ads:ads-adservices", [BuildType.MAIN])
 includeProject(":privacysandbox:ads:ads-adservices-java", [BuildType.MAIN])
+includeProject(":privacysandbox:plugins:plugins-privacysandbox-library", [BuildType.MAIN])
 includeProject(":privacysandbox:sdkruntime:sdkruntime-client", [BuildType.MAIN])
 includeProject(":privacysandbox:sdkruntime:sdkruntime-core", [BuildType.MAIN])
 includeProject(":privacysandbox:tools:tools", [BuildType.MAIN])