Replace annotation_processors with plugins

The annotation_processors property is deprecated, replace it with
plugins, and use java_plugin for modules that provide annotation
processors.

Bug: 77284273
Test: m checkbuild
Change-Id: I14ed4d81e097510866cbb9a27c72be4426117885
diff --git a/Android.bp b/Android.bp
index 81a9850..0c88471 100644
--- a/Android.bp
+++ b/Android.bp
@@ -741,11 +741,7 @@
     name: "framework-annotation-proc",
     defaults: ["framework-defaults"],
     // Use UsedByApps annotation processor
-    annotation_processors: ["unsupportedappusage-annotation-processor"],
-    // b/25860419: annotation processors must be explicitly specified for grok
-    annotation_processor_classes: [
-        "android.processor.unsupportedappusage.UsedByAppsProcessor",
-    ],
+    plugins: ["unsupportedappusage-annotation-processor"],
 }
 
 // A host library including just UnsupportedAppUsage.java so that the annotation